Fair Use of Domain Reg Info?

[Chris]

This morning I got a call on a phone that is not a published number.  The
only place it appears is on a domain record (a NetSol domain) I have.

It was from ValueWeb, and the person on the phone couldn't tell me where
they got the information for calling me on a cell phone to use my air time
:)

So, it occurred to me that there must be some guidelines for use of the
domain name registration info on a domain.  Anyone know what guidelines
there are or where they are published?

Chris