Down-level Filesets on AIX
Investigating the issue with the 'oslevel' command
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.