Question

I was implementing my own Attribute today when i noticed the virtual function Match.
The normal implementation of Match is to call Equals, so why does it exist in the first place?

The documentation says the following for Match

When overridden in a derived class, returns a value that indicates
whether this instance equals a specified object.

The documentation says the following for Equals

Returns a value that indicates whether this instance is equal to a
specified object.

Answer 1

The remarks section in MSDN for that method explains their difference:

This method determines if one Attribute equals another. Its default implementation is the same as Equals, which performs a value and reference comparison. Override this method to implement support for attribute values, such as flags or bit fields, that consist of components that are meaningful in themselves.

For example, consider an attribute whose value is a binary field divided into a bit field of flags. Two instances of this attribute have one flag in set in common while all the other flags differ. The Equals method cannot determine that the two instances have the same flag set, but the Match method can.