AIX Levels are named based on Release, Technology Level, Service Pack, and Build Sequence Identifier e.g. 7100-05-04-1914. As well as the current OS level, the oslevel command can show details of the TLs and SPs on a server along with details of any up- or down-level filesets.
I have been working with IBM AIX for almost 28 years, starting with v3.2.5. Over the years I have considered taking the various certification exams that IBM used to offer but never got around to organising it.