ULN Views 11 meanings found ULN may refer to academic or legal networks, the medical reference "upper limits of normal", the capital of Mongolia, or various governmental identifiers. Medical Upper Limits of Normal Ulnar Miscellaneous Unique Learner Number Unbreakable Linux Network Universal Linear and N Governmental United Legal Network Unit Line Number Ultra Low Noise Academic & Science University Leadership Network Upper Limit of Normal Regional Ulan Bator, Mongolia