I am asked what the heck them "93's" are all about. I apologize for not thinking of explaining this before, and append an excerpt from one of my posts on the late, great Ceremonial Magick boards of a large, metropolitan ISP. ;)
The numerical greetings are a sort of shorthand among Thelemites* for the standard Thelemic greetings. Y'see, the Greek numeration for "Will" ("Thelema") and "Love" ("Agape") totals -- in each case -- 93.
So the shorthand for "Do what thou wilt shall be the whole of the Law" is "93!" (for Thelema, Will); and for "Love is the law, love under will," it's "93 93/93", with a sort of math joke incorporated (Agape, Thelema/Agape -- "love under will," get it?).
The identical number for both terms is considered significant, too: as though asserting a basic identity between Love, and one's "True Will."
Aleister Crowley himself came up with the numerical shorthand for these greetings. Lotsa Thelemites, myself included, find it chattier and less formal to toss around 93's, than to begin each post "Do what thou wilt shall be the whole of the Law," and end it "Love is the law, love under will."
Why would one want to use any such formula? Speaking only for myself, it's simultaneously a greeting, a sign-countersign (in speech)**, and a reminder to all and sundry of their natural freedom....and the responsibility that comes with it. :)
Hope that helps, & delighted to see you here! :D
93 93/93 -- AJ
* "Thelemites": adherents to "Thelema," a spiritual-magical teaching, philosophy, and (for some) religion, associated with Edward Alexander "Aleister" Crowley (1875-1947), English mystic, magician, poet and philosopher.
** The full and formal version is to greet someone (in person) with "Do what thou wilt shall be the whole of the Law"; if they're a Thelemite, they will themselves reply, "Love is the law, love under will." This too can be shortened to "93!", "93!" At large gatherings of Thelemites, one is very grateful for the shorthand version...heh.