What's possible in hints file?

Gurus, normally, I would do a short check, but currently I've no connection to one of my running FR, but have to plan some extensions. Has someone of you done something like the following? Regarding 'hints' - file: Would it be possible to use - $INCLUDE /path/file? - Fall-Trough? - temp A/V pairs defined in the global dictionary file using an ID > 3000 and using them as %{My-Attribute} later on? Thank you. Regards Stefan