The following package provides a functionality for an object to create/delete comment boxes on the right handside as modeling nodes. For this purpose the "HOTSPOT" functionality of the GraphRep is combined with a "Pragramcall"-attribute to create/delete the comment box as you can see below.
Download:
Library
Track Changes - Create_CommentBox_Library v1.0.abl
AdoScripts
WriteComment.asc ClearComment.asc ADOxx Realisation Hands On:
1) MODELING LANGUAGE:
Create the following four classes:The above mentioned HOTSPOT for creating a comment box is placed on the right upper corner of the object and is marked with a pen in a rectangle.

You can find the HOTSPOT for deleting the comment box right upper corner of the comment box.