Many of the prior posts are cogent. I personally, with most of my partnerships, play a lower/lower cue-bid system (i.e., if you opened 1c, 2h would be a L/R+ in clubs, and 2s forcing with d's; if you opened 1d, 2h FORCING with clubs, and 2s l/r+ in d's). Such a system allows for non-forcing bids of 2d and 3c, and 3c and 3d, respectively, and to show both good hands and hands that merely want to compete. The important thing is to have agreements thereafter against a 2-suited o/c system: Let say it goes 1d-2d(o/c) by the PITA opps, and you bid 2h (forcing with clubs)-- you need to establish whether a subsequent bid of 2s or 3h by partner SHOWS a stopper, or asks for one, in an effort to get to 3n or 5 of a minor.