Michael J. Swart has a script which helps you find system-generated constraint names:
Names for constraints are optional meaning that if you don’t provide a name when it’s created or cannot afford one, one will be appointed to you by the system.
These system provided names are messy things and I don’t think I have to discourage you from using them. Kenneth Fisher has already done that in Constraint names, Say NO to the default.But how do you know whether you have any?
Check out the informative comments as well.