Searching for a Technical Bulletin? As of May 20th, Technical Bulletins have been replaced by ATIs or Additional Technical Information documents. ATIs are attached to specific tests in ARUP’s Laboratory Test Directory (LTD). They provide answers to frequently requested technical information and are easy to access and read. ATIs may answer your questions about test interpretation, additional tests to consider, or other technical aspects of a test. It may even save you a call to Client Services. Please watch the video below for more information.