Many people play that a with trump low bid has priority over a with trump high bid of the same number. For example if one player bids 4 high, the next player can overcall with 4 low. On the other hand, some play that all bids for a given number of tricks are equal - so for example to overcall a 4 bid of any kind requires a 5 bid or higher. Some play that if the bidding is won by a with trumps bid, the kitty must be sported , before it is added to the bidder's hand. Sporting the kitty means that after a player wins the bid they expose the kitty, so that all can see what cards are in it.
Some players play with only one joker, and therefore only five cards in the kitty.
Some players play with only one joker, but use the deuce of spades as permanent second highest trump in the game. In this case there is only a five card kitty, and the spade suit is shorter than the others, the two counting as part of the trump suit. In no trump bids, the two of spades resumes its normal function as a spade. Some players play with both jokers and with the deuce of spades as the third highest trump in the game. In this case there is a six card kitty.