ProjectSchema.xml

<?xml version="1.0" encoding="utf-8"?>
<ProjectSchemaDefinitions xmlns="http://schemas.microsoft.com/build/2009/properties" xmlns:sys="clr-namespace:System;assembly=mscorlib">
  <ItemType Name="CsCompile" DisplayName="C# compiler"/>
  <ContentType Name="CsCode" DisplayName="C# code" ItemType="CsCompile" />
  <FileExtension Name=".cs" ContentType="CsCode"/>
  <Rule Name="CsCompile" PageTemplate="tool" DisplayName="C#" Order="11">
    <Rule.DataSource>
      <DataSource Persistence="ProjectFile" ItemType="CsCompile" />
    </Rule.DataSource>
    <Rule.Categories>
      <Category Name="General" DisplayName="General" />
      <Category Name="Advanced" DisplayName="Advanced" />
      <Category Name="All Options" DisplayName="All Options" Subtype="Search" />
    </Rule.Categories>
    <EnumProperty Name="LangVersion" DisplayName="Language Version">
      <EnumValue Name="default" DisplayName="Default" Description="Accept all valid language syntax." />
      <EnumValue Name="ISO-1" DisplayName="ISO-1" Description="Accept only syntax that is included in the ISO/IEC 23270:2003 C# language specification." />
      <EnumValue Name="ISO-2" DisplayName="ISO-2" Description="Accept only syntax that is included in the ISO/IEC 23270:2006 C# language specification." />
      <EnumValue Name="3" DisplayName="3.0" Description="Accept only syntax that is included in the version 3.0 C# language Specification." />
      <EnumValue Name="4" DisplayName="4.0" Description="Accept only syntax that is included in the version 4.0 C# language Specification." />
      <EnumValue Name="5" DisplayName="5.0" Description="Accept only syntax that is included in the version 5.0 C# language Specification." />
    </EnumProperty>
    <BoolProperty Name="Optimize" DisplayName="Optimize" Category="General" />
    <BoolProperty Name="AllowUnsafeBlocks" DisplayName="Allow Unsafe Code" Category="General" />
    <EnumProperty Name="WarningLevel" DisplayName="Warning Level" Category="General" >
      <EnumValue Name="0" DisplayName="Turn Off All Warnings" />
      <EnumValue Name="1" DisplayName="Level1" />
      <EnumValue Name="2" DisplayName="Level2" />
      <EnumValue Name="3" DisplayName="Level3" />
      <EnumValue Name="4" DisplayName="Level4" />
    </EnumProperty>
    <StringListProperty Name="NoWarn" DisplayName="Disable Specific Warnings" Category="Advanced" />
    <StringListProperty Name="WarningsAsErrors" DisplayName="Treat Specific Warnings As Errors" Category="Advanced" />
    <StringListProperty Name="WarningsNotAsErrors" DisplayName="Treat Specific Warnings Not As Errors" Category="Advanced" />
  </Rule>
</ProjectSchemaDefinitions>