UIC 568 cable

[WatsonPD]

Just found a document from RSSB which shows most of the train interconnection systems in Britain, and there's one thing about UIC 568 cable - what does “ECML” stand for? mk4 coach? I know Nightstock means the Night Star coaches.

 

[Supercoss]

East Coast Main Line , where the Mark 4 push pull stock operated.

 

[WatsonPD]

East Coast Main Line , where the Mark 4 push pull stock operated

But there's another system for cl91/mk4
which looks like a modified 568 though
so why there are two versions?

 

[Nym]

It uses UIC cable and connectors, but not the UIC standard for communications.