Andreas suggested...

>you may run POSIXCBT.LSN.SYS
>This is a Computer Based Training for Posix/HFS.

In case you prefer a written manual (paper or web), you might also
have a look at "New Features ... Hierarchical File System ..." (the
exact title escapes me at present, but you should be able to find
it either in the Communicator/3000 appendix on available manuals,
or at the docs.hp.com web site).

Lars (the manuals aren't too bad, sometimes)

PS: On Posix Shell and Utils there is some related User's Guide, too.