Raise of Opening 1 Bid
A raise of 1 of a minor in Standard American normally promises 5 or more in the suit since opener may have as few as 3 ("Convenient Minor").
With a good hand, if responder has 5+ of opener's minor and also has 4+ cards in another suit, responder bids the other suit first, but with a weak hand, responder may only be able to bid once, and must show his trump support right away, even if it means not bidding a 4-card major.
The same applies with 4+ Spades and 3+ Hearts when partner has opened 1H. Responder must raise with a weak hand rather than showing his Spade suit.
Common conventional raises include: