Use the Category/Cue limit when you want the sound to be stopped with a release.
Example: An elevator has a start sound (A) and a stop sound (B). Assign both (A) and (B) to the Category "Elevator."
Set the Cue Limit of the Category "Elevator" to 1.
Note that if the release is too long, the sounds will overlap and this will use the resources for a longer time.