No-limit spread-limit hold 'em is a made-up term to describe a form of poker that has developed in California and Arizona casinos. It is played almost identically to No-limit hold 'em, but it does have an upper limit on the amount of any bet or raise, as in Spread-limit hold 'em. However, that upper limit is so high that it is not acting as the throttle that the spread does in spread-limit, and instead is clearly there solely to placate local authorities.
Many localities in California regulate gambling to some degree, and a few of them do so by regulating the "maximum amount of any wager". Casinos interpret this to mean the maximum amount of any particular bet or raise. In Northern California, a few localities restrict wagers to no more than $200, so a form of "spread limit $4-$200" poker has been created. This plays just like no-limit except that the maximum individual bet or raise is $200 at any time. Since buyins at these games are typically only $200 max, it nearly always plays identically to no-limit anyway, but the rules satisfy the legal authorities.
Incidentally, a story I heard from a dealer says that until around 2000 or so, San Jose's maximum wagering law was even being applied to the play money used in tournaments! Since the casinos were not allowed to have even play money wagers over $200, only limit tournaments were played, and blinds and such started at something like 5 play dollars to ensure they could never get above $200.