There are people who like to claim that they are put upon and exploited. Sometimes this may indeed be true. With others it becomes a habit of behaviour: 'poor me'.
Code 13/13 is a reminder not to play that card too often.

There are people who go through life blaming everything on a miserable childhood, abuse, an accident, etc. While the event may be perfectly true, the need to blame everything on the event is often exaggerated. It is used as an excuse for everything.

The same may be true of an incident in the earlier part of a relationship. This may be brought up on every occasion as a sort of weapon.

Code 13/13 points out the exaggeration in such attitudes.