Stuart,
I want you to know why I was confused on the question. FL (fixed limit) is what you were looking for. There are games that are defined as flexible limit also. I know that you are not as versed in cash games as you are in tournament games, otherwise I know you would have all the answers you need. For your information, fixed limit and structured betting are the same. This is where each betting round has a fixed amount. Example; 5 and 10 limit texas hold'em, blinds 2/5, bets $5 (pre-flop) $5 after the flop, $10 after the turn and $10 after the river. Bets and raises can only be made in those incriments. UTG calls $5 BB, next player raises to $10 ($5 more, which is the only allowable raise). Next player raises to $15 ($5 more). On the last two betting rounds in a flop game, the structured limit doubles.
Flexible limit is also defined as a "spread limit." Most casinos that feature 7-card stud will use a spread limit. An example would be a $1 to $5 stud. Players may wager any incriment within that range. Example 5th street, player in the 2 seat is high with two aces, he may check or bet $1, $2, $3, $4 or $5. There is usually a three raise limit, but some casinos use four, i.e. Ballagio for low limit stud.
I would also like to add that years ago, at the Tropicana in Las Vegas, we actually spread a $2 to $10 hold'em game that went over with great success. I don't know why more cardrooms don't use it today.
There are also mixed limit games, too. I hope this helps.