You can use the Tag property to store any extra information about a form, report, data access page, section, or control needed by your application.
Setting
You can enter a string expression up to 2048 characters long. The default setting is a zero-length string (" ").
You can set this property by using the object's property sheet, a macro, or Visual Basic.
Remarks
Unlike other properties, the Tag property setting doesn't affect any of an object's attributes.
You can use this property to assign an identification string to an object without affecting any of its other property settings or causing other side effects. The Tag property is useful when you need to check the identity of a form, report, data access page, section, or control that is passed as a variable to a procedure.