Technote QD 06 | November 1987 |
The idea here is to provide a "metacomment" which will contain information about which application owns the comment as well as the comment itself:
ApplicationComment (long comment) kind = 100 size = n + 6 data = application signature (i.e. 'MPNT' for MacPaint) = 4 bytes application "local" kind = 2 bytes comment data = n bytes
In this way each comment may be specific to an application. It is still up to a developer to publish information about the comments they have defined if they wish them to be understood and used by other programs.
Previously assigned and registered comments will still be valid. This means that those defined for the LaserWriter or MacDraw, for instance, will retain their normal meaning.
Suppose your application (creator = 'MYAP') wanted to define a comment. The appearance of the comment would be as follows (assuming you chose 128 to be the "local" kind for the comment):
kind = 100; data = 'MYAP' [4 bytes] + 128 [2 bytes] + additional data