Copyright language for fan produced sourcebooks?

[Olefin]

Does anyone have a standard boiler plate notice that we need to put on fan issued modules or sourcebooks so we dont violate copyright or licensing agreements on any of the various versions of Twilight 2000?

I have seen such statements on the Czech and Mexican Army guides but not sure if there is one agreed on statement that can be used across the board for any new authors, like myself, who are doing such material?

If this has been posted before can anyone please point out which thread has it?

Thank you