Tucked away in the Appendices to the Laws of Chess are the specific rules for Rapidplay and Blitz. To summarise the main points:
(A.1) Rapidplay is where each player has between 15 and 59 minutes to complete the game.
(A.2) You do not have to record your moves.
(A.4d) An arbiter shall refrain from signalling flag fall (unlike in standard play), unless both flags are down.
(B.1) Blitz is where each player has fewer than 15 minutes to complete the game.
(B.3b) FIDE Rule 10.2 does not apply.
(B.3c) An illegal move loses, provided the opponent claims before making his move. If the claimant cannot checkmate, then he can claim a draw instead.
If you are playing in a Rapidplay event, such as the Cambridgeshire Rapidplay in Peterborough this coming Sunday (21 April), be sure to check up on the relevant rules before you go!
NB. There will be no further postings this weekend as I’m off to Bristol this evening. Next one will be on Monday.