From PubNight

When playing a game of dominos, or when such a thing is being considered, every opportunity should be taken to make one of the following announcements.

These should supplement, rather than supplant, correct use of the gambits and scoring slogans.

Cornell's postulate : The double seven never scores

The Cornell refutation : "The double seven never scores" should be said very loudly whenever it does

The Groves' threshold : The time at night at which it is too late to start a game of doms

The Groves' limitation : Only normal threes and fives should be played

Hall's Allegation : Anybody after Syd never scores

Black's Quandary : Which of the two 11|3s should I play?

BM's Proposal : Before the next hand should we get the next round in?

He's Morrising :  This announcement should be made when somebody reaches the high 90's but then fails to score, with the risk - and hope of the rest of the players - that somebody else will either catch up, or overtake and win.

In addition to the above mentioned Doms based announcements, additional ritual statements subsist.  These include:

Whenever (or at least the first time of an evening) that a pint of Charles Wells' excellent Bombardier is ordered, all present (well, all who feel like it) shall intone in a Tolkieneske fashion "Ho Tom Bombardier, Tom Bombadildo", and repeat until threatened with violence (ie, not repeat very much at all).

It is important to explain what a pint of Tribute isn't