Actually, "less than" means it must be less than the limit you set, and "no more" than can mean it can include the limit set. For example, say the limit is 1.
a) "Less than" 1 means it can be anything up to 0.99999~, but never 1.
b) "No more than" 1 means it can be anything up to, and including 1.
The difference is subtle, but it depends on the accuracy you desire.