What does the filterpriority tag in an XML comment do?

Question

I have seen this in a lot of XML comments for classes in the .NET Framework BCL but have never been able to find documentation that explains what it does.

As an example, looking at System.Object reveals the following comments:

namespace System   
{
    /// <summary>Supports all classes in the .NET Framework class hierarchy 
    /// and provides low-level services to derived classes. This is the 
    /// ultimate base class of all classes in the .NET Framework; it is the
    /// root of the type hierarchy.</summary>
    /// <filterpriority>1</filterpriority> 
    [System.Runtime.InteropServices.ClassInterfaceAttribute(2)]
    public class Object    
    {    
        /// <summary>Determines whether the specified 
        /// <see cref="T:System.Object" /> 
        /// instances are considered equal.</summary>  
        /// <returns>true if objA is the same instance as objB or
        /// if both are null
        /// references or if objA.Equals(objB) returns true; 
        /// otherwise, false.</returns>
        /// <param name="objB">The second <see cref="T:System.Object" /> 
        /// to compare. </param>
        /// <param name="objA">The first <see cref="T:System.Object" /> 
        /// to compare. </param>
        /// <filterpriority>2</filterpriority>
        public static bool Equals(object objA, object objB);
     }
 }

Answer 1

Just a guess: the All vs Common tabs in intellisense?

Answer 2

It is the same as decorating your member with EditorBrowsableAttribute. I would guess values 0,1 and 2 corresponds to Always, Advanced and Never.