I usually use the Comments feature of the Source Control in two ways:
1. The normal way, i.e. as the comment for a Commit
2. A note before "Commit". But, using it as a note is quite awkward because it will not stick with the database. When moving to another database, the note will become the note for current database.
I wish that the every database can have its own Comment to stick with before Commit so that it will not accidentally commit with the wrong comments.