ILL is the general term - "ISO ILL" - Usually refers to ISO10161/10160 (Which can be run over TCP or (s)/Mime substrates)
To avoid confusion, we always say ISO18626 when referring to that
But we should always say ISO10161/tcp and ISO10161/smime when we mean that
And generally stop saying "ISO ILL"
When I’ve suggested that we use 18626 as the lingua franca, my idea had been that it might be possible to use the newer, leaner spec as the reference model internally rather than lumpy bloaty 10161… as I recall it contains lotsa things we wouldn’t care about…. and then have adapters for 10161 when needed…
But I’ve not done any actual analysis on whether that makes sense… but 18626 is the living document with an active community around it…