while many of the suggestions sound good, they're still substituting one mouthful of initials for another mouthful of initials.

If we want the initials to be easy to remember, they need to spell something.

Here's a couple of not-very-good examples, but they'll get the point across

C.H.I.P.S.....
Casino
History
International
Preservation
Society

G.A.M.E.S....
Gambling
And
Memorable
Educational
Society

C.H.E.Q.U.E.S...
Collecting
Historical
Ephemera
Qualifies
Unique
Educational
Status

You get the idea....