There are two temperature control limits that can be set during or after commissioning.
User Limits - These are used to control what the desired temperatures will be allowed to be set to controlling the limits the user or occupants have the ability to choose. These are typically used to tighten a band so that equipment isn't competing with each other within a building.
User limits also contribute to your setback temperatures. [Read about your setback Temp here]
Building Limits - These are mostly used for alerting on building temp. There is an alert that is triggered whenever any zone with priority in a building breaches one of these critical limits.