From OpenSCADAWiki
The tag can be accessed as to "read" and also to "write", therefore an element of the triad of access may be:
- 00 — there is no any access;
- 04 — there is an access only for reading;
- 02 — there is only access fro the writing, usually this value has no meaning because the write access means access for reading;
- 06 — there is an access to read, and to write.