Hi,
The help files says,
Stores additional information about an object.
Syntax
object.Tag [= String]
The Tag property syntax has these parts:
Part Description
object Required. A valid object.
String Optional. A string expression identifying the object. The default
is a zero-length string ("").
Remarks
Use the Tag property to assign an identification string to an object
without affecting other property settings or attributes.
For example, you can use Tag to check the identity of a form or control
that is passed as a variable to a procedure.
Cheers
Andy