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="All Options" DisplayName="All Options" Subtype="Search" />
    </Rule.Categories>
    <BoolProperty Name="Optimize" DisplayName="Optimize" Category="General" />
    <StringListProperty Name="NoWarn" DisplayName="Disable Specific Warnings" Category="General" />
  </Rule>
</ProjectSchemaDefinitions>