From OpenSCADAWiki
The "Messages" tab (Fig.4.6i) contains the form of the messages request from the archive of the archiver:
- Time, depth and level — specifies the request date and time, depth and minimum level of messages (more or equal).
- Category pattern — indicates the category of the requested messages. In the category you can specify the elements of selection by template, that is the characters '*' — for any string and '?' — for any character, as well as a regular expression enclosed between the symbols '/' (/mod_(System|LogicLev)/).