diff --git a/.eslintignore b/.eslintignore
index 6168af4..8e61a52 100644
--- a/.eslintignore
+++ b/.eslintignore
@@ -1,4 +1,5 @@
 node_modules/
-dist
 coverage
 jest.config.js
+schema-dts/lib/
+schema-dts/dist/
diff --git a/packages/schema-dts-gen/src/transform/toClass.ts b/packages/schema-dts-gen/src/transform/toClass.ts
index f79df36..f07948a 100644
--- a/packages/schema-dts-gen/src/transform/toClass.ts
+++ b/packages/schema-dts-gen/src/transform/toClass.ts
@@ -18,9 +18,11 @@ import {Log} from '../logging/index.js';
 import {ObjectPredicate, Topic, TypedTopic} from '../triples/triple.js';
 import {UrlNode} from '../triples/types.js';
 import {
-  IsNamedClass,
+  IsDirectlyNamedClass,
   IsDataType,
   ClassIsDataType,
+  IsNamedUrl,
+  IsSubclass,
 } from '../triples/wellKnown.js';
 import {
   AliasBuiltin,
@@ -29,7 +31,7 @@ import {
   DataTypeUnion,
   RoleBuiltin,
 } from '../ts/class.js';
-import {assert} from '../util/assert.js';
+import {assert, asserted, assertIs} from '../util/assert.js';
 
 function toClass(cls: Class, topic: Topic, map: ClassMap): Class {
   const rest: ObjectPredicate[] = [];
@@ -61,11 +63,21 @@ const wellKnownTypes = [
   new AliasBuiltin('http://schema.org/Date', AliasBuiltin.Alias('string')),
   new AliasBuiltin('http://schema.org/DateTime', AliasBuiltin.Alias('string')),
   new AliasBuiltin('http://schema.org/Boolean', AliasBuiltin.Alias('boolean')),
-  new RoleBuiltin(UrlNode.Parse('http://schema.org/Role')),
-  new RoleBuiltin(UrlNode.Parse('http://schema.org/OrganizationRole')),
-  new RoleBuiltin(UrlNode.Parse('http://schema.org/EmployeeRole')),
-  new RoleBuiltin(UrlNode.Parse('http://schema.org/LinkRole')),
-  new RoleBuiltin(UrlNode.Parse('http://schema.org/PerformanceRole')),
+  new RoleBuiltin(
+    asserted(UrlNode.Parse('http://schema.org/Role'), IsNamedUrl)
+  ),
+  new RoleBuiltin(
+    asserted(UrlNode.Parse('http://schema.org/OrganizationRole'), IsNamedUrl)
+  ),
+  new RoleBuiltin(
+    asserted(UrlNode.Parse('http://schema.org/EmployeeRole'), IsNamedUrl)
+  ),
+  new RoleBuiltin(
+    asserted(UrlNode.Parse('http://schema.org/LinkRole'), IsNamedUrl)
+  ),
+  new RoleBuiltin(
+    asserted(UrlNode.Parse('http://schema.org/PerformanceRole'), IsNamedUrl)
+  ),
 ];
 
 // Should we allow 'string' to be a valid type for all values of this type?
@@ -90,7 +102,13 @@ function ForwardDeclareClasses(topics: readonly TypedTopic[]): ClassMap {
     if (IsDataType(topic.Subject)) {
       classes.set(topic.Subject.toString(), dataType);
       continue;
-    } else if (!IsNamedClass(topic)) continue;
+    } else if (!IsDirectlyNamedClass(topic) && !IsSubclass(topic)) continue;
+
+    if (!IsNamedUrl(topic.Subject)) {
+      throw new Error(
+        `Unexpected unnamed URL ${topic.Subject.toString()} as a class.`
+      );
+    }
 
     const wk = wellKnownTypes.find(wk => wk.subject.equivTo(topic.Subject));
     if (ClassIsDataType(topic)) {
@@ -108,6 +126,7 @@ function ForwardDeclareClasses(topics: readonly TypedTopic[]): ClassMap {
       wks.equivTo(topic.Subject)
     );
     if (allowString) cls.addTypedef(AliasBuiltin.Alias('string'));
+    if (IsDirectlyNamedClass(topic)) cls.markAsExplicitClass();
 
     classes.set(topic.Subject.toString(), cls);
   }
@@ -117,12 +136,16 @@ function ForwardDeclareClasses(topics: readonly TypedTopic[]): ClassMap {
 
 function BuildClasses(topics: readonly TypedTopic[], classes: ClassMap) {
   for (const topic of topics) {
-    if (!IsNamedClass(topic)) continue;
+    if (!IsDirectlyNamedClass(topic) && !IsSubclass(topic)) continue;
 
     const cls = classes.get(topic.Subject.toString());
     assert(cls);
     toClass(cls, topic, classes);
   }
+
+  for (const cls of classes.values()) {
+    cls.validateClass();
+  }
 }
 
 /**
diff --git a/packages/schema-dts-gen/src/triples/reader.ts b/packages/schema-dts-gen/src/triples/reader.ts
index 5ab3261..614c41c 100644
--- a/packages/schema-dts-gen/src/triples/reader.ts
+++ b/packages/schema-dts-gen/src/triples/reader.ts
@@ -53,7 +53,7 @@ function object(content: string) {
 }
 
 const totalRegex =
-  /\s*<([^<>]+)>\s*<([^<>]+)>\s*((?:<[^<>"]+>)|(?:"(?:[^"]|(?:\\"))+(?:[^\"]|\\")"(?:@[a-zA-Z]+)?))\s*\./;
+  /\s*<([^<>]+)>\s*<([^<>]+)>\s*((?:<[^<>"]+>)|(?:"(?:[^"]|(?:\\"))*(?:[^\"]|\\")"(?:@[a-zA-Z]+)?))\s*\./;
 export function toTripleStrings(data: string[]) {
   const linearTriples = data
     .join('')
@@ -215,7 +215,9 @@ export function* process(triples: string[][]): Iterable<Triple> {
     } catch (parseError) {
       const e = parseError as Error;
       throw new Error(
-        `ParseError: ${e.name}: ${e.message} while parsing line ${match}.\nOriginal Stack:\n${e.stack}\nRethrown from:`
+        `ParseError: ${e.name}: ${e.message} while parsing line ${match
+          .map(t => `\{${t}\}`)
+          .join(', ')}.\nOriginal Stack:\n${e.stack}\nRethrown from:`
       );
     }
   }
diff --git a/packages/schema-dts-gen/src/triples/triple.ts b/packages/schema-dts-gen/src/triples/triple.ts
index 48fad48..5c2df9b 100644
--- a/packages/schema-dts-gen/src/triples/triple.ts
+++ b/packages/schema-dts-gen/src/triples/triple.ts
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {Rdfs, SchemaString, UrlNode} from './types.js';
+import {NamedUrlNode, Rdfs, SchemaString, UrlNode} from './types.js';
 
 /** Represents a parsed Subject-Predicate-Object statement. */
 export interface Triple {
@@ -41,7 +41,7 @@ export interface ObjectPredicate {
  * A Node that can correspond to a "concept" in the ontology (class, property,
  * etc.).
  */
-export type TTypeName = UrlNode;
+export type TTypeName = NamedUrlNode;
 
 /** A set of statements applying to the same Subject. */
 export interface Topic {
diff --git a/packages/schema-dts-gen/src/triples/types.ts b/packages/schema-dts-gen/src/triples/types.ts
index 704efd2..271fcd1 100644
--- a/packages/schema-dts-gen/src/triples/types.ts
+++ b/packages/schema-dts-gen/src/triples/types.ts
@@ -24,8 +24,7 @@ export interface ReadonlyUrl {
   readonly path: readonly string[];
   readonly search: string;
 }
-function fromString(urlString: string): ReadonlyUrl {
-  const url = new URL(urlString);
+function fromUrl(url: URL): ReadonlyUrl {
   return {
     href: url.href,
     protocol: url.protocol,
@@ -34,6 +33,9 @@ function fromString(urlString: string): ReadonlyUrl {
     search: url.search,
   };
 }
+function fromString(urlString: string): ReadonlyUrl {
+  return fromUrl(new URL(urlString));
+}
 function pathEqual(first: readonly string[], second: readonly string[]) {
   if (first.length !== second.length) return false;
   for (let i = 0; i < first.length; ++i) {
@@ -50,7 +52,7 @@ function pathEqual(first: readonly string[], second: readonly string[]) {
 export class UrlNode {
   readonly type = 'UrlNode';
   constructor(
-    readonly name: string,
+    readonly name: string | undefined,
     readonly context: ReadonlyUrl,
     readonly href: string
   ) {}
@@ -101,21 +103,25 @@ export class UrlNode {
     }
 
     if (url.search) {
-      throw new Error(
-        `Can't handle Search string in ${url.search} in ${url.href}`
+      // A URL with no hash but some "?..." search params
+      // should be treated the same as an unnamed URL.
+      return new UrlNode(
+        /*name=*/ undefined,
+        /*context=*/ fromUrl(url),
+        /*href=*/ url.href
       );
     }
 
     const split = url.pathname.split('/');
-    const name = split.pop();
-    if (!name) {
-      throw new Error(`Unexpected URL ${url.href} with no room for 'name'.`);
-    }
+    let name = split.pop();
+    if (name === '') name = undefined;
+
     const context = url.origin + split.join('/');
 
     return new UrlNode(name, fromString(context), url.href);
   }
 }
+export type NamedUrlNode = UrlNode & {name: string};
 
 /**
  * In-memory representation of a node in a Triple corresponding to a string
diff --git a/packages/schema-dts-gen/src/triples/wellKnown.ts b/packages/schema-dts-gen/src/triples/wellKnown.ts
index 5588dc5..d638d65 100644
--- a/packages/schema-dts-gen/src/triples/wellKnown.ts
+++ b/packages/schema-dts-gen/src/triples/wellKnown.ts
@@ -21,7 +21,7 @@ import {
   TTypeName,
   TypedTopic,
 } from './triple.js';
-import {UrlNode} from './types.js';
+import {NamedUrlNode, UrlNode} from './types.js';
 
 /** Whether the context corresponds to rdf-schema. */
 export function IsRdfSchema(value: UrlNode): boolean {
@@ -43,6 +43,13 @@ export function IsRdfSyntax(value: UrlNode): boolean {
 export function IsSchemaObject(value: UrlNode): boolean {
   return value.context.hostname === 'schema.org';
 }
+/** Wheter the context corresponds to OWL */
+export function IsOWL(value: UrlNode): boolean {
+  return (
+    value.context.hostname === 'www.w3.org' &&
+    value.context.path[value.context.path.length - 1] === 'owl'
+  );
+}
 
 /**
  * If an ObjectPredicate represents a comment, returns the comment. Otherwise
@@ -66,20 +73,35 @@ export function GetComment(value: ObjectPredicate): {comment: string} | null {
  */
 export function GetSubClassOf(
   value: ObjectPredicate
-): {subClassOf: TSubject} | null {
+): {subClassOf: TTypeName} | null {
   if (IsRdfSchema(value.Predicate) && value.Predicate.name === 'subClassOf') {
     if (value.Object.type === 'SchemaString' || value.Object.type === 'Rdfs') {
       throw new Error(
         `Unexpected object for predicate 'subClassOf': ${value.Object}.`
       );
     }
+    if (!IsNamedUrl(value.Object)) {
+      throw new Error(
+        `Unexpected "unnamed" URL used as a super-class: ${value.Object}`
+      );
+    }
     return {subClassOf: value.Object};
   }
   return null;
 }
 
+/** Return true iff this object is a subclass of some other entity. */
+export function IsSubclass(topic: TypedTopic) {
+  return topic.values.some(op => GetSubClassOf(op) !== null);
+}
+
+/** Returns true iff a UrlNode has a "name" it can be addressed with. */
+export function IsNamedUrl(t: UrlNode): t is NamedUrlNode {
+  return t.name !== undefined;
+}
+
 /** Returns true iff a node corresponds to http://schema.org/DataType */
-export function IsDataType(t: TTypeName): boolean {
+export function IsDataType(t: TSubject): boolean {
   return IsSchemaObject(t) && t.name === 'DataType';
 }
 
@@ -89,8 +111,17 @@ export function ClassIsDataType(topic: TypedTopic): boolean {
   return false;
 }
 
-/** Returns true iff a Topic represents a named class. */
-export function IsNamedClass(topic: TypedTopic): boolean {
+/**
+ * Returns true iff a Topic represents a named class.
+ *
+ * Note that some schemas define subclasses without explicitly redefining them
+ * as classes. So just because a topic isn't directly named as a class doesn't
+ * mean that it isn't a named class.
+ *
+ * A named class is such if it *OR ANY OF ITS PARENTS* are directly named
+ * classes.
+ */
+export function IsDirectlyNamedClass(topic: TypedTopic): boolean {
   // Skip anything that isn't a class.
   return topic.types.some(IsClassType);
 }
@@ -99,13 +130,19 @@ export function IsNamedClass(topic: TypedTopic): boolean {
  * Returns true iff a Predicate corresponds to http://schema.org/domainIncludes
  */
 export function IsDomainIncludes(value: TPredicate): boolean {
-  return IsSchemaObject(value) && value.name === 'domainIncludes';
+  return (
+    (IsSchemaObject(value) && value.name === 'domainIncludes') ||
+    (IsRdfSchema(value) && value.name === 'domain')
+  );
 }
 /**
  * Returns true iff a Predicate corresponds to http://schema.org/rangeIncludes
  */
 export function IsRangeIncludes(value: TPredicate): boolean {
-  return IsSchemaObject(value) && value.name === 'rangeIncludes';
+  return (
+    (IsSchemaObject(value) && value.name === 'rangeIncludes') ||
+    (IsRdfSchema(value) && value.name === 'range')
+  );
 }
 /**
  * Returns true iff a Predicate corresponds to http://schema.org/supersededBy.
@@ -150,19 +187,9 @@ export function GetTypes(
 ): readonly TTypeName[] {
   const types = values.map(GetType).filter((t): t is TTypeName => !!t);
 
-  if (types.length === 0) {
-    throw new Error(
-      `No type found for Subject ${key.toString()}. Triples include:\n${values
-        .map(
-          v =>
-            `${v.Predicate.toString()}: ${JSON.stringify(
-              v.Predicate
-            )}\n\t=> ${v.Object.toString()}`
-        )
-        .join('\n')}`
-    );
-  }
-
+  // Allow empty types. Some custom schema assume "transitive" typing, e.g.
+  // gs1 has a TypeCode class which is an rdfs:Class, but its subclasses are
+  // not explicitly described as an rdfs:Class.
   return types;
 }
 
@@ -170,7 +197,7 @@ export function GetTypes(
  * Returns true iff a Type corresponds to
  * http://www.w3.org/2000/01/rdf-schema#Class
  */
-export function IsClassType(type: TTypeName): boolean {
+export function IsClassType(type: UrlNode): boolean {
   return IsRdfSchema(type) && type.name === 'Class';
 }
 
@@ -193,6 +220,25 @@ export function HasEnumType(types: readonly TTypeName[]): boolean {
     // Skip well-known types.
     if (IsClassType(type) || IsPropertyType(type) || IsDataType(type)) continue;
 
+    // Skip OWL "meta" types:
+    if (IsOWL(type)) {
+      if (
+        [
+          'Ontology',
+          'Class',
+          'DatatypeProperty',
+          'ObjectProperty',
+          'FunctionalProperty',
+          'InverseFunctionalProperty',
+          'AnnotationProperty',
+          'SymmetricProperty',
+          'TransitiveProperty',
+        ].includes(type.name)
+      ) {
+        continue;
+      }
+    }
+
     // If we're here, this is a 'Type' that is not well known.
     return true;
   }
diff --git a/packages/schema-dts-gen/src/ts/class.ts b/packages/schema-dts-gen/src/ts/class.ts
index 57316b0..30e3951 100644
--- a/packages/schema-dts-gen/src/ts/class.ts
+++ b/packages/schema-dts-gen/src/ts/class.ts
@@ -24,16 +24,14 @@ import type {
 const {factory, ModifierFlags, SyntaxKind} = ts;
 
 import {Log} from '../logging/index.js';
-import {TObject, TPredicate, TSubject} from '../triples/triple.js';
+import {TObject, TPredicate, TSubject, TTypeName} from '../triples/triple.js';
 import {UrlNode} from '../triples/types.js';
 import {
   GetComment,
   GetSubClassOf,
   IsSupersededBy,
   IsClassType,
-  IsDataType,
-  IsType,
-  IsTypeName,
+  IsNamedUrl,
 } from '../triples/wellKnown.js';
 
 import {Context} from './context.js';
@@ -42,7 +40,7 @@ import {Property, TypeProperty} from './property.js';
 import {arrayOf} from './util/arrayof.js';
 import {appendLine, withComments} from './util/comments.js';
 import {toClassName} from './util/names.js';
-import {assert} from '../util/assert.js';
+import {assert, asserted} from '../util/assert.js';
 import {IdReferenceName} from './helper_types.js';
 import {typeUnion} from './util/union.js';
 
@@ -64,6 +62,7 @@ export class Class {
   private _comment?: string;
   private _typedefs: TypeNode[] = [];
   private _isDataType = false;
+  private _explicitlyMarkedAsClass = false;
   private readonly children: Class[] = [];
   private readonly _parents: Class[] = [];
   private readonly _props: Set<Property> = new Set();
@@ -153,7 +152,7 @@ export class Class {
     return toClassName(this.subject);
   }
 
-  constructor(readonly subject: TSubject) {}
+  constructor(readonly subject: TTypeName) {}
   add(
     value: {Predicate: TPredicate; Object: TObject},
     classMap: ClassMap
@@ -207,6 +206,25 @@ export class Class {
   addTypedef(typedef: TypeNode) {
     this._typedefs.push(typedef);
   }
+  markAsExplicitClass() {
+    this._explicitlyMarkedAsClass = true;
+  }
+  private isMarkedAsClass(visited: WeakSet<Class>): boolean {
+    if (visited.has(this)) return false;
+    visited.add(this);
+
+    return (
+      this._explicitlyMarkedAsClass ||
+      this._parents.some(p => p.isMarkedAsClass(visited))
+    );
+  }
+  validateClass(): void {
+    if (!this.isMarkedAsClass(new WeakSet())) {
+      throw new Error(
+        `Class ${this.className()} is not marked as an rdfs:Class, and neither are any of its parents.`
+      );
+    }
+  }
 
   addProp(p: Property) {
     this._props.add(p);
@@ -385,7 +403,12 @@ export class Class {
 /**
  * Represents a DataType.
  */
-export class Builtin extends Class {}
+export class Builtin extends Class {
+  constructor(subject: TTypeName) {
+    super(subject);
+    this.markAsExplicitClass();
+  }
+}
 
 /**
  * A "Native" Schema.org object that is best represented
@@ -393,7 +416,7 @@ export class Builtin extends Class {}
  */
 export class AliasBuiltin extends Builtin {
   constructor(url: string, ...equivTo: TypeNode[]) {
-    super(UrlNode.Parse(url));
+    super(asserted(UrlNode.Parse(url), IsNamedUrl));
     for (const t of equivTo) this.addTypedef(t);
   }
 
@@ -510,7 +533,7 @@ export class RoleBuiltin extends Builtin {
 
 export class DataTypeUnion extends Builtin {
   constructor(url: string, readonly wk: Builtin[]) {
-    super(UrlNode.Parse(url));
+    super(asserted(UrlNode.Parse(url), IsNamedUrl));
   }
 
   toNode(): DeclarationStatement[] {
@@ -565,7 +588,7 @@ export function Sort(a: Class, b: Class): number {
 }
 
 function CompareKeys(a: TSubject, b: TSubject): number {
-  const byName = a.name.localeCompare(b.name);
+  const byName = (a.name || '').localeCompare(b.name || '');
   if (byName !== 0) return byName;
 
   return a.href.localeCompare(b.href);
diff --git a/packages/schema-dts-gen/src/ts/context.ts b/packages/schema-dts-gen/src/ts/context.ts
index 4fa3bc2..fc3011c 100644
--- a/packages/schema-dts-gen/src/ts/context.ts
+++ b/packages/schema-dts-gen/src/ts/context.ts
@@ -57,7 +57,15 @@ export class Context {
   getScopedName(node: TSubject): string {
     for (const [name, url] of this.context) {
       if (node.matchesContext(url)) {
-        return name === '' ? node.name : `${name}:${node.name}`;
+        // Valid possibilities:
+        // - "schema:Foo"  when name == schema && node.name == Foo.
+        // - "schema:"     when name == schema && node.name is undefined.
+        // - "Foo"         when name is empty and node.name is Foo.
+        //
+        // Don't allow "" when name is empty and  node.name is undefined.
+        return name === ''
+          ? node.name ?? node.toString()
+          : `${name}:${node.name || ''}`;
       }
     }
     return node.toString();
diff --git a/packages/schema-dts-gen/src/ts/enum.ts b/packages/schema-dts-gen/src/ts/enum.ts
index 5bd33af..34d3b10 100644
--- a/packages/schema-dts-gen/src/ts/enum.ts
+++ b/packages/schema-dts-gen/src/ts/enum.ts
@@ -18,11 +18,12 @@ import type {TypeNode} from 'typescript';
 const {factory} = ts;
 
 import {Log} from '../logging/index.js';
-import {ObjectPredicate, TSubject, TTypeName} from '../triples/triple.js';
+import {ObjectPredicate, TSubject} from '../triples/triple.js';
 import {GetComment, IsClassType, IsDataType} from '../triples/wellKnown.js';
 
 import {ClassMap} from './class.js';
 import {Context} from './context.js';
+import {UrlNode} from '../index.js';
 
 /**
  * Corresponds to a value that belongs to an Enumeration.
@@ -33,7 +34,7 @@ export class EnumValue {
   private comment?: string;
   constructor(
     readonly value: TSubject,
-    types: readonly TTypeName[],
+    types: readonly UrlNode[],
     map: ClassMap
   ) {
     for (const type of types) {
diff --git a/packages/schema-dts-gen/src/util/assert.ts b/packages/schema-dts-gen/src/util/assert.ts
index 7b9699a..a61f313 100644
--- a/packages/schema-dts-gen/src/util/assert.ts
+++ b/packages/schema-dts-gen/src/util/assert.ts
@@ -22,3 +22,20 @@ export function assert<T>(
 ): asserts item is T {
   ok(item, message);
 }
+
+export function assertIs<T, U extends T>(
+  item: T,
+  assertion: (i: T) => i is U,
+  message?: string
+): asserts item is U {
+  ok(assertion(item), message);
+}
+
+export function asserted<T, U extends T>(
+  item: T,
+  assertion: (i: T) => i is U,
+  message?: string
+): U {
+  assertIs(item, assertion, message);
+  return item;
+}
diff --git a/packages/schema-dts-gen/test/baselines/invalid_schemas_test.ts b/packages/schema-dts-gen/test/baselines/invalid_schemas_test.ts
new file mode 100644
index 0000000..53ea6a6
--- /dev/null
+++ b/packages/schema-dts-gen/test/baselines/invalid_schemas_test.ts
@@ -0,0 +1,66 @@
+/**
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @fileoverview Baseline tests are a set of tests (in tests/baseline/) that
+ * correspond to full comparisons of a generate .ts output based on a set of
+ * Triples representing an entire ontology.
+ */
+import {basename} from 'path';
+
+import {inlineCli} from '../helpers/main_driver.js';
+
+test(`invalidSyntax_${basename(import.meta.url)}`, async () => {
+  const run = inlineCli(
+    `
+ <"INVALID> <http://www.w3.org/1999/02/22-rdf-s> "X" .
+       `,
+    ['--ontology', `https://fake.com/${basename(import.meta.url)}.nt`]
+  );
+
+  await expect(run).rejects.toThrowError('ParseError');
+});
+
+test(`unnamedURLClass_${basename(import.meta.url)}`, async () => {
+  const run = inlineCli(
+    `
+ <http://schema.org/> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+       `,
+    ['--ontology', `https://fake.com/${basename(import.meta.url)}.nt`]
+  );
+
+  await expect(run).rejects.toThrowError('Unexpected unnamed URL');
+});
+
+test(`notMarkedAsClass_cycle_${basename(import.meta.url)}`, async () => {
+  const run = inlineCli(
+    `
+ <http://schema.org/name> <http://schema.org/rangeIncludes> <http://schema.org/Text> .
+ <http://schema.org/name> <http://schema.org/domainIncludes> <http://schema.org/Thing> .
+ <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Property> .
+ <http://schema.org/Thing> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+ <http://schema.org/Thing> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Person> .
+ <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+ <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Thing> .
+ <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/DataType> .
+ <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+ <http://schema.org/Text> <http://www.w3.org/2000/01/rdf-schema#comment> "Data type: Text." .
+       `,
+    ['--ontology', `https://fake.com/${basename(import.meta.url)}.nt`]
+  );
+
+  await expect(run).rejects.toThrowError(
+    'Thing is not marked as an rdfs:Class'
+  );
+});
diff --git a/packages/schema-dts-gen/test/baselines/owl_mixed_basic_test.ts b/packages/schema-dts-gen/test/baselines/owl_mixed_basic_test.ts
new file mode 100644
index 0000000..e30ebb8
--- /dev/null
+++ b/packages/schema-dts-gen/test/baselines/owl_mixed_basic_test.ts
@@ -0,0 +1,203 @@
+/**
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @fileoverview Baseline tests are a set of tests (in tests/baseline/) that
+ * correspond to full comparisons of a generate .ts output based on a set of
+ * Triples representing an entire ontology.
+ */
+import {basename} from 'path';
+
+import {inlineCli} from '../helpers/main_driver.js';
+
+test(`baseline_mixedOWL1_${basename(import.meta.url)}`, async () => {
+  const {actual} = await inlineCli(
+    `
+   <http://schema.org/name> <http://schema.org/rangeIncludes> <http://schema.org/Text> .
+   <http://schema.org/name> <http://schema.org/domainIncludes> <http://schema.org/Thing> .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Property> .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#FunctionalProperty> .
+   <http://schema.org/Thing> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#Class> .
+   <http://schema.org/Thing> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+   <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+   <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Thing> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/DataType> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+   <http://schema.org/Text> <http://www.w3.org/2000/01/rdf-schema#comment> "Data type: Text." .
+         `,
+    ['--ontology', `https://fake.com/${basename(import.meta.url)}.nt`]
+  );
+
+  expect(actual).toMatchInlineSnapshot(`
+"/** Used at the top-level node to indicate the context for the JSON-LD objects used. The context provided in this type is compatible with the keys and URLs in the rest of this generated file. */
+export type WithContext<T extends Thing> = T & {
+    \\"@context\\": \\"https://schema.org\\";
+};
+export interface Graph {
+    \\"@context\\": \\"https://schema.org\\";
+    \\"@graph\\": readonly Thing[];
+}
+type SchemaValue<T> = T | readonly T[];
+type IdReference = {
+    /** IRI identifying the canonical address of this object. */
+    \\"@id\\": string;
+};
+
+/** Data type: Text. */
+export type Text = string;
+
+interface PersonLeaf extends ThingBase {
+    \\"@type\\": \\"Person\\";
+}
+/** ABC */
+export type Person = PersonLeaf | string;
+
+interface ThingBase extends Partial<IdReference> {
+    \\"name\\"?: SchemaValue<Text>;
+}
+interface ThingLeaf extends ThingBase {
+    \\"@type\\": \\"Thing\\";
+}
+/** ABC */
+export type Thing = ThingLeaf | Person;
+
+"
+`);
+});
+
+test(`baseline_mixedOWL2_${basename(import.meta.url)}`, async () => {
+  const {actual} = await inlineCli(
+    `
+   <http://schema.org/name> <http://www.w3.org/2000/01/rdf-schema#range> <http://schema.org/Text> .
+   <http://schema.org/name> <http://www.w3.org/2000/01/rdf-schema#domain> <http://schema.org/Thing> .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Property> .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#DatatypeProperty> .
+   <http://schema.org/Thing> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#Class> .
+   <http://schema.org/Thing> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+   <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+   <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Thing> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/DataType> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#Class> .
+   <http://schema.org/Text> <http://www.w3.org/2000/01/rdf-schema#comment> "Data type: Text." .
+         `,
+    ['--ontology', `https://fake.com/${basename(import.meta.url)}.nt`]
+  );
+
+  expect(actual).toMatchInlineSnapshot(`
+"/** Used at the top-level node to indicate the context for the JSON-LD objects used. The context provided in this type is compatible with the keys and URLs in the rest of this generated file. */
+export type WithContext<T extends Thing> = T & {
+    \\"@context\\": \\"https://schema.org\\";
+};
+export interface Graph {
+    \\"@context\\": \\"https://schema.org\\";
+    \\"@graph\\": readonly Thing[];
+}
+type SchemaValue<T> = T | readonly T[];
+type IdReference = {
+    /** IRI identifying the canonical address of this object. */
+    \\"@id\\": string;
+};
+
+/** Data type: Text. */
+export type Text = string;
+
+interface PersonLeaf extends ThingBase {
+    \\"@type\\": \\"Person\\";
+}
+/** ABC */
+export type Person = PersonLeaf | string;
+
+interface ThingBase extends Partial<IdReference> {
+    \\"name\\"?: SchemaValue<Text>;
+}
+interface ThingLeaf extends ThingBase {
+    \\"@type\\": \\"Thing\\";
+}
+/** ABC */
+export type Thing = ThingLeaf | Person;
+
+"
+`);
+});
+
+test(`baseline_OWLenum_${basename(import.meta.url)}`, async () => {
+  const {actual} = await inlineCli(
+    `
+   <http://schema.org/name> <http://www.w3.org/2000/01/rdf-schema#range> <http://schema.org/Text> .
+   <http://schema.org/name> <http://www.w3.org/2000/01/rdf-schema#domain> <http://schema.org/Thing> .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Property> .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#DatatypeProperty> .
+   <http://schema.org/Thing> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+   <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#Class> .
+   <http://schema.org/Thing> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+   <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+   <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Thing> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/DataType> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+   <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#Class> .
+   <http://schema.org/Text> <http://www.w3.org/2000/01/rdf-schema#comment> "Data type: Text." .
+   <http://www.w3.org/2002/07/owl#MyEnum> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+   <http://www.w3.org/2002/07/owl#MyEnum> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#Class> .
+   <http://www.w3.org/2002/07/owl#EnumValueA> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#MyEnum> .
+   <http://www.w3.org/2002/07/owl#EnumValueB> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2002/07/owl#MyEnum> .
+         `,
+    ['--ontology', `https://fake.com/${basename(import.meta.url)}.nt`]
+  );
+
+  expect(actual).toMatchInlineSnapshot(`
+"/** Used at the top-level node to indicate the context for the JSON-LD objects used. The context provided in this type is compatible with the keys and URLs in the rest of this generated file. */
+export type WithContext<T extends Thing> = T & {
+    \\"@context\\": \\"https://schema.org\\";
+};
+export interface Graph {
+    \\"@context\\": \\"https://schema.org\\";
+    \\"@graph\\": readonly Thing[];
+}
+type SchemaValue<T> = T | readonly T[];
+type IdReference = {
+    /** IRI identifying the canonical address of this object. */
+    \\"@id\\": string;
+};
+
+/** Data type: Text. */
+export type Text = string;
+
+interface MyEnumBase extends Partial<IdReference> {
+}
+interface MyEnumLeaf extends MyEnumBase {
+    \\"@type\\": \\"http://www.w3.org/2002/07/owl#MyEnum\\";
+}
+export type MyEnum = \\"http://www.w3.org/2002/07/owl#EnumValueA\\" | \\"https://www.w3.org/2002/07/owl#EnumValueA\\" | \\"http://www.w3.org/2002/07/owl#EnumValueB\\" | \\"https://www.w3.org/2002/07/owl#EnumValueB\\" | MyEnumLeaf;
+
+interface PersonLeaf extends ThingBase {
+    \\"@type\\": \\"Person\\";
+}
+/** ABC */
+export type Person = PersonLeaf | string;
+
+interface ThingBase extends Partial<IdReference> {
+    \\"name\\"?: SchemaValue<Text>;
+}
+interface ThingLeaf extends ThingBase {
+    \\"@type\\": \\"Thing\\";
+}
+/** ABC */
+export type Thing = ThingLeaf | Person;
+
+"
+`);
+});
diff --git a/packages/schema-dts-gen/test/baselines/transitive_class_test.ts b/packages/schema-dts-gen/test/baselines/transitive_class_test.ts
new file mode 100644
index 0000000..d737c46
--- /dev/null
+++ b/packages/schema-dts-gen/test/baselines/transitive_class_test.ts
@@ -0,0 +1,76 @@
+/**
+ * Copyright 2022 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @fileoverview Baseline tests are a set of tests (in tests/baseline/) that
+ * correspond to full comparisons of a generate .ts output based on a set of
+ * Triples representing an entire ontology.
+ */
+import {basename} from 'path';
+
+import {inlineCli} from '../helpers/main_driver.js';
+
+test(`baseline_${basename(import.meta.url)}`, async () => {
+  const {actual} = await inlineCli(
+    `
+  <http://schema.org/name> <http://schema.org/rangeIncludes> <http://schema.org/Text> .
+  <http://schema.org/name> <http://schema.org/domainIncludes> <http://schema.org/Thing> .
+  <http://schema.org/name> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Property> .
+  <http://schema.org/Thing> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+  <http://schema.org/Thing> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+  <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#comment> "ABC" .
+  <http://schema.org/Person> <http://www.w3.org/2000/01/rdf-schema#subClassOf> <http://schema.org/Thing> .
+  <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/DataType> .
+  <http://schema.org/Text> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/2000/01/rdf-schema#Class> .
+  <http://schema.org/Text> <http://www.w3.org/2000/01/rdf-schema#comment> "Data type: Text." .
+        `,
+    ['--ontology', `https://fake.com/${basename(import.meta.url)}.nt`]
+  );
+
+  expect(actual).toMatchInlineSnapshot(`
+"/** Used at the top-level node to indicate the context for the JSON-LD objects used. The context provided in this type is compatible with the keys and URLs in the rest of this generated file. */
+export type WithContext<T extends Thing> = T & {
+    \\"@context\\": \\"https://schema.org\\";
+};
+export interface Graph {
+    \\"@context\\": \\"https://schema.org\\";
+    \\"@graph\\": readonly Thing[];
+}
+type SchemaValue<T> = T | readonly T[];
+type IdReference = {
+    /** IRI identifying the canonical address of this object. */
+    \\"@id\\": string;
+};
+
+/** Data type: Text. */
+export type Text = string;
+
+interface PersonLeaf extends ThingBase {
+    \\"@type\\": \\"Person\\";
+}
+/** ABC */
+export type Person = PersonLeaf | string;
+
+interface ThingBase extends Partial<IdReference> {
+    \\"name\\"?: SchemaValue<Text>;
+}
+interface ThingLeaf extends ThingBase {
+    \\"@type\\": \\"Thing\\";
+}
+/** ABC */
+export type Thing = ThingLeaf | Person;
+
+"
+`);
+});
diff --git a/packages/schema-dts-gen/test/helpers/make_class.ts b/packages/schema-dts-gen/test/helpers/make_class.ts
index 56be2ef..4059028 100644
--- a/packages/schema-dts-gen/test/helpers/make_class.ts
+++ b/packages/schema-dts-gen/test/helpers/make_class.ts
@@ -13,11 +13,17 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {UrlNode} from '../../src/triples/types.js';
+import {Property, PropertyType} from '../../src/index.js';
+import {NamedUrlNode, UrlNode} from '../../src/triples/types.js';
 import {Class, ClassMap} from '../../src/ts/class.js';
 
 export function makeClass(url: string): Class {
-  return new Class(UrlNode.Parse(url));
+  return new Class(UrlNode.Parse(url) as NamedUrlNode);
+}
+
+export function makeProperty(url: string): Property {
+  const u = UrlNode.Parse(url);
+  return new Property(u, new PropertyType(u));
 }
 
 export function makeClassMap(...classes: Class[]): ClassMap {
diff --git a/packages/schema-dts-gen/test/triples/reader_test.ts b/packages/schema-dts-gen/test/triples/reader_test.ts
index b795043..f7c0b6b 100644
--- a/packages/schema-dts-gen/test/triples/reader_test.ts
+++ b/packages/schema-dts-gen/test/triples/reader_test.ts
@@ -54,7 +54,7 @@ describe('load', () => {
     get.mockReturnValueOnce(firstReturn);
     firstReturn.destroy(new Error('Bad!!!'));
 
-    await expect(triples$.toPromise()).rejects.toThrow('Bad!!!');
+    await expect(firstValueFrom(triples$)).rejects.toThrow('Bad!!!');
 
     expect(get).toBeCalledTimes(1);
   });
@@ -174,7 +174,7 @@ describe('load', () => {
       ]);
     });
 
-    it('Multiple (throws from bad URL: Subject)', async () => {
+    it('Multiple (works with unnamed URL: subject)', async () => {
       const control = fakeResponse(200, 'Ok');
       control.data(
         `<https://schema.org/Person> <https://schema.org/knowsAbout> "math" .\n`
@@ -184,39 +184,70 @@ describe('load', () => {
       );
       control.end();
 
-      await expect(triples).rejects.toThrow(
-        'ParseError: Error: Unexpected URL'
-      );
+      await expect(triples).resolves.toEqual([
+        {
+          Subject: UrlNode.Parse('https://schema.org/Person'),
+          Predicate: UrlNode.Parse('https://schema.org/knowsAbout'),
+          Object: SchemaString.Parse('"math"')!,
+        },
+        {
+          Subject: UrlNode.Parse('http://schema.org/'),
+          Predicate: UrlNode.Parse(
+            'http://www.w3.org/2000/01/rdf-schema#comment'
+          ),
+          Object: SchemaString.Parse('"A test comment."')!,
+        },
+      ]);
     });
 
-    it('Multiple (throws from bad URL: Predicate)', async () => {
+    it('Multiple (works with search URL)', async () => {
       const control = fakeResponse(200, 'Ok');
       control.data(
         `<https://schema.org/Person> <https://schema.org/knowsAbout> "math" .\n`
       );
       control.data(
-        `<http://schema.org/A> <https://schema.org> "A test comment." .\n`
+        `<https://schema.org/X?A=B> <http://www.w3.org/2000/01/rdf-schema#comment> "A test comment." .\n`
       );
       control.end();
 
-      await expect(triples).rejects.toThrow(
-        'ParseError: Error: Unexpected URL'
-      );
+      await expect(triples).resolves.toEqual([
+        {
+          Subject: UrlNode.Parse('https://schema.org/Person'),
+          Predicate: UrlNode.Parse('https://schema.org/knowsAbout'),
+          Object: SchemaString.Parse('"math"')!,
+        },
+        {
+          Subject: UrlNode.Parse('https://schema.org/X?A=B'),
+          Predicate: UrlNode.Parse(
+            'http://www.w3.org/2000/01/rdf-schema#comment'
+          ),
+          Object: SchemaString.Parse('"A test comment."')!,
+        },
+      ]);
     });
 
-    it('Multiple (throws from bad URL: Object)', async () => {
+    it('Multiple (works with unnamed URL: predicate)', async () => {
       const control = fakeResponse(200, 'Ok');
       control.data(
-        `<https://schema.org/Person> <https://schema.org/knowsAbout> <https://schema.org/> .\n`
+        `<https://schema.org/Person> <https://schema.org/knowsAbout> "math" .\n`
       );
       control.data(
-        `<http://schema.org/A> <http://www.w3.org/2000/01/rdf-schema#comment> "A test comment." .\n`
+        `<http://schema.org/A> <https://schema.org> "A test comment." .\n`
       );
       control.end();
 
-      await expect(triples).rejects.toThrow(
-        'ParseError: Error: Unexpected URL'
-      );
+      await expect(triples).resolves.toEqual([
+        {
+          Subject: UrlNode.Parse('https://schema.org/Person'),
+          Predicate: UrlNode.Parse('https://schema.org/knowsAbout'),
+          Object: SchemaString.Parse('"math"')!,
+        },
+        {
+          Subject: UrlNode.Parse('http://schema.org/A'),
+          Predicate: UrlNode.Parse('https://schema.org'),
+          Object: SchemaString.Parse('"A test comment."')!,
+        },
+      ]);
     });
 
     it('Multiple (dirty broken)', async () => {
diff --git a/packages/schema-dts-gen/test/triples/types_test.ts b/packages/schema-dts-gen/test/triples/types_test.ts
index 3eade69..d356903 100644
--- a/packages/schema-dts-gen/test/triples/types_test.ts
+++ b/packages/schema-dts-gen/test/triples/types_test.ts
@@ -47,35 +47,15 @@ describe('UrlNode', () => {
     expect(node.context.path).toEqual(['']);
   });
 
-  it('rejects search strings', () => {
-    expect(() =>
-      UrlNode.Parse('http://schema.org/Person?q=true&a')
-    ).toThrowError('Search string');
-
-    expect(() => UrlNode.Parse('http://schema.org/Person?q&a')).toThrowError(
-      'Search string'
-    );
-
-    expect(() => UrlNode.Parse('http://schema.org/Person?q')).toThrowError(
-      'Search string'
-    );
-
-    expect(() =>
-      UrlNode.Parse('http://schema.org/abc?q#foo')
-    ).not.toThrowError();
-    expect(() => UrlNode.Parse('http://schema.org/abc#?q')).not.toThrowError();
+  it('treats search strings as unnamed', () => {
+    const node = UrlNode.Parse('http://schema.org/Person?q=true&a');
+    expect(node.name).toBeUndefined();
+    expect(node.context.href).toBe('http://schema.org/Person?q=true&a');
   });
 
-  it('top-level domain', () => {
-    expect(() => UrlNode.Parse('http://schema.org/')).toThrowError(
-      "no room for 'name'"
-    );
-
-    expect(() => UrlNode.Parse('http://schema.org')).toThrowError(
-      "no room for 'name'"
-    );
-
-    expect(() => UrlNode.Parse('http://schema.org/#foo')).not.toThrowError();
+  it('treats top-level domain as unnamed', () => {
+    expect(UrlNode.Parse('http://schema.org/').name).toBeUndefined();
+    expect(UrlNode.Parse('http://schema.org').name).toBeUndefined();
   });
 
   describe('matches context', () => {
diff --git a/packages/schema-dts-gen/test/triples/wellKnown_test.ts b/packages/schema-dts-gen/test/triples/wellKnown_test.ts
index 3810082..3e44dc0 100644
--- a/packages/schema-dts-gen/test/triples/wellKnown_test.ts
+++ b/packages/schema-dts-gen/test/triples/wellKnown_test.ts
@@ -13,13 +13,18 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {Rdfs, SchemaString, UrlNode} from '../../src/triples/types.js';
+import {
+  NamedUrlNode,
+  Rdfs,
+  SchemaString,
+  UrlNode,
+} from '../../src/triples/types.js';
 import {
   GetComment,
   GetSubClassOf,
   GetType,
   GetTypes,
-  IsNamedClass,
+  IsDirectlyNamedClass,
 } from '../../src/triples/wellKnown.js';
 
 describe('wellKnown', () => {
@@ -123,6 +128,26 @@ describe('wellKnown', () => {
         })
       ).toThrowError('Unexpected object for predicate');
     });
+
+    it('only supports named UrlNodes as parents', () => {
+      expect(() =>
+        GetSubClassOf({
+          Predicate: UrlNode.Parse(
+            'http://www.w3.org/2000/01/rdf-schema#subClassOf'
+          ),
+          Object: UrlNode.Parse('https://schema.org/'),
+        })
+      ).toThrowError('Unexpected "unnamed" URL used as a super-class');
+
+      expect(() =>
+        GetSubClassOf({
+          Predicate: UrlNode.Parse(
+            'http://www.w3.org/2000/01/rdf-schema#subClassOf'
+          ),
+          Object: UrlNode.Parse('https://schema.org'),
+        })
+      ).toThrowError('Unexpected "unnamed" URL used as a super-class');
+    });
   });
 
   describe('GetType', () => {
@@ -234,39 +259,20 @@ describe('wellKnown', () => {
         UrlNode.Parse('http://schema.org/Thing'),
       ]);
     });
-
-    it('Throws if none', () => {
-      expect(() =>
-        GetTypes(UrlNode.Parse('https://schema.org/Widget'), [])
-      ).toThrowError('No type found');
-
-      expect(() =>
-        GetTypes(UrlNode.Parse('https://schema.org/Widget'), [
-          {
-            Predicate: UrlNode.Parse(
-              'http://www.w3.org/1999/02/22-rdf-syntax-ns#property'
-            ),
-            Object: UrlNode.Parse('http://www.w3.org/2000/01/rdf-schema#Class'),
-          },
-          {
-            Predicate: UrlNode.Parse(
-              'http://www.w3.org/2000/01/rdf-schema#label'
-            ),
-            Object: new SchemaString('Thing', undefined),
-          },
-        ])
-      ).toThrowError('No type found');
-    });
   });
 
-  describe('IsNamedClass', () => {
-    const cls = UrlNode.Parse('http://www.w3.org/2000/01/rdf-schema#Class');
-    const dataType = UrlNode.Parse('http://schema.org/DataType');
-    const bool = UrlNode.Parse('http://schema.org/Boolean');
+  describe('IsDirectlyNamedClass', () => {
+    const cls = UrlNode.Parse(
+      'http://www.w3.org/2000/01/rdf-schema#Class'
+    ) as NamedUrlNode;
+    const dataType = UrlNode.Parse(
+      'http://schema.org/DataType'
+    ) as NamedUrlNode;
+    const bool = UrlNode.Parse('http://schema.org/Boolean') as NamedUrlNode;
 
     it('a data type is a named class', () => {
       expect(
-        IsNamedClass({
+        IsDirectlyNamedClass({
           Subject: UrlNode.Parse('https://schema.org/Text'),
           types: [cls, dataType],
           values: [],
@@ -274,7 +280,7 @@ describe('wellKnown', () => {
       ).toBe(true);
 
       expect(
-        IsNamedClass({
+        IsDirectlyNamedClass({
           Subject: UrlNode.Parse('https://schema.org/Text'),
           types: [dataType, cls],
           values: [],
@@ -284,7 +290,7 @@ describe('wellKnown', () => {
 
     it('an only-enum is not a class', () => {
       expect(
-        IsNamedClass({
+        IsDirectlyNamedClass({
           Subject: UrlNode.Parse('https://schema.org/True'),
           types: [bool],
           values: [],
@@ -294,7 +300,7 @@ describe('wellKnown', () => {
 
     it('an enum can still be a class', () => {
       expect(
-        IsNamedClass({
+        IsDirectlyNamedClass({
           Subject: UrlNode.Parse('https://schema.org/ItsComplicated'),
           types: [bool, cls],
           values: [],
@@ -304,7 +310,7 @@ describe('wellKnown', () => {
 
     it('the DataType union is a class', () => {
       expect(
-        IsNamedClass({
+        IsDirectlyNamedClass({
           Subject: UrlNode.Parse('https://schema.org/DataType'),
           types: [cls],
           values: [
diff --git a/packages/schema-dts-gen/test/ts/class_test.ts b/packages/schema-dts-gen/test/ts/class_test.ts
index 83a3eec..21c82d3 100644
--- a/packages/schema-dts-gen/test/ts/class_test.ts
+++ b/packages/schema-dts-gen/test/ts/class_test.ts
@@ -16,7 +16,7 @@
 
 import ts from 'typescript';
 
-import {SchemaString, UrlNode} from '../../src/triples/types.js';
+import {NamedUrlNode, SchemaString, UrlNode} from '../../src/triples/types.js';
 import {
   AliasBuiltin,
   Class,
@@ -25,7 +25,7 @@ import {
   Builtin,
 } from '../../src/ts/class.js';
 import {Context} from '../../src/ts/context.js';
-import {makeClass, makeClassMap} from '../helpers/make_class.js';
+import {makeClass, makeClassMap, makeProperty} from '../helpers/make_class.js';
 
 describe('Class', () => {
   let cls: Class;
@@ -235,6 +235,36 @@ describe('Class', () => {
       ).toThrowError('unknown node type');
     });
   });
+
+  describe('property sorting', () => {
+    const ctx = new Context();
+    ctx.addNamedContext('schema', 'https://schema.org/');
+
+    it('alphabetic, respecting empty', () => {
+      const cls = makeClass('https://schema.org/A');
+      cls.addProp(makeProperty('https://schema.org/a'));
+      cls.addProp(makeProperty('https://schema.org/b'));
+      cls.addProp(makeProperty('https://schema.org/'));
+      cls.addProp(makeProperty('https://schema.org/c'));
+      cls.addProp(makeProperty('https://abc.com/e'));
+      cls.addProp(makeProperty('https://abc.com'));
+
+      expect(asString(cls, ctx)).toMatchInlineSnapshot(`
+"interface ABase extends Partial<IdReference> {
+    \\"https://abc.com/\\"?: SchemaValue<never>;
+    \\"schema:\\"?: SchemaValue<never>;
+    \\"schema:a\\"?: SchemaValue<never>;
+    \\"schema:b\\"?: SchemaValue<never>;
+    \\"schema:c\\"?: SchemaValue<never>;
+    \\"https://abc.com/e\\"?: SchemaValue<never>;
+}
+interface ALeaf extends ABase {
+    \\"@type\\": \\"schema:A\\";
+}
+export type A = ALeaf;"
+`);
+    });
+  });
 });
 
 describe('Sort(Class, Class)', () => {
@@ -362,7 +392,7 @@ describe('Sort(Class, Class)', () => {
       // Can be same as less specific builtins.
       expect(
         Sort(
-          new Builtin(UrlNode.Parse('https://schema.org/Boo')),
+          new Builtin(UrlNode.Parse('https://schema.org/Boo') as NamedUrlNode),
           new AliasBuiltin('https://schema.org/Boo', AliasBuiltin.Alias('Text'))
         )
       ).toBe(0);
diff --git a/packages/schema-dts-gen/test/ts/context_test.ts b/packages/schema-dts-gen/test/ts/context_test.ts
index e7d9048..31ba8f9 100644
--- a/packages/schema-dts-gen/test/ts/context_test.ts
+++ b/packages/schema-dts-gen/test/ts/context_test.ts
@@ -143,6 +143,13 @@ describe('Context.getScopedName', () => {
     expect(ctx.getScopedName(UrlNode.Parse('https://foo.org/Door'))).toBe(
       'https://foo.org/Door'
     );
+
+    expect(ctx.getScopedName(UrlNode.Parse('https://schema.org/'))).toBe(
+      'https://schema.org/'
+    );
+    expect(ctx.getScopedName(UrlNode.Parse('https://schema.org'))).toBe(
+      'https://schema.org/'
+    );
   });
 
   it('with single domain URL (http)', () => {
@@ -185,6 +192,12 @@ describe('Context.getScopedName', () => {
     expect(ctx.getScopedName(UrlNode.Parse('http://foo.org/Door'))).toBe(
       'http://foo.org/Door'
     );
+    expect(ctx.getScopedName(UrlNode.Parse('http://schema.org/'))).toBe(
+      'schema:'
+    );
+    expect(ctx.getScopedName(UrlNode.Parse('http://schema.org'))).toBe(
+      'schema:'
+    );
   });
 });
 
diff --git a/packages/schema-dts-gen/test/ts/names_test.ts b/packages/schema-dts-gen/test/ts/names_test.ts
index 5ae1dc7..3e5452b 100644
--- a/packages/schema-dts-gen/test/ts/names_test.ts
+++ b/packages/schema-dts-gen/test/ts/names_test.ts
@@ -13,43 +13,43 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import {UrlNode} from '../../src/triples/types.js';
+import {NamedUrlNode, UrlNode} from '../../src/triples/types.js';
 import {toClassName} from '../../src/ts/util/names.js';
 
+function parseNamed(url: string): NamedUrlNode {
+  return UrlNode.Parse(url) as NamedUrlNode;
+}
+
 describe('toClassName', () => {
   it('operates normally, with typical inputs', () => {
-    expect(toClassName(UrlNode.Parse('https://schema.org/Person'))).toBe(
-      'Person'
-    );
-    expect(toClassName(UrlNode.Parse('https://schema.org/Person3'))).toBe(
+    expect(toClassName(parseNamed('https://schema.org/Person'))).toBe('Person');
+    expect(toClassName(parseNamed('https://schema.org/Person3'))).toBe(
       'Person3'
     );
-    expect(toClassName(UrlNode.Parse('http://schema.org/Person'))).toBe(
-      'Person'
-    );
+    expect(toClassName(parseNamed('http://schema.org/Person'))).toBe('Person');
     expect(
-      toClassName(UrlNode.Parse('http://schema.org/Organization4Organization'))
+      toClassName(parseNamed('http://schema.org/Organization4Organization'))
     ).toBe('Organization4Organization');
   });
 
   it('handles illegal TypeScript identifier characters', () => {
-    expect(toClassName(UrlNode.Parse('https://schema.org/Person-4'))).toBe(
+    expect(toClassName(parseNamed('https://schema.org/Person-4'))).toBe(
       'Person_4'
     );
-    expect(toClassName(UrlNode.Parse('https://schema.org/Person%4'))).toBe(
+    expect(toClassName(parseNamed('https://schema.org/Person%4'))).toBe(
       'Person_4'
     );
-    expect(toClassName(UrlNode.Parse('https://schema.org/Person%204'))).toBe(
+    expect(toClassName(parseNamed('https://schema.org/Person%204'))).toBe(
       'Person_4'
     );
-    expect(toClassName(UrlNode.Parse('https://schema.org/Person, 4'))).toBe(
+    expect(toClassName(parseNamed('https://schema.org/Person, 4'))).toBe(
       'Person__4'
     );
 
-    expect(toClassName(UrlNode.Parse('https://schema.org/3DModel'))).toBe(
+    expect(toClassName(parseNamed('https://schema.org/3DModel'))).toBe(
       '_3DModel'
     );
-    expect(toClassName(UrlNode.Parse('https://schema.org/3DModel-5'))).toBe(
+    expect(toClassName(parseNamed('https://schema.org/3DModel-5'))).toBe(
       '_3DModel_5'
     );
   });