You need do nothing. that's new EG7, but the old EG7 says:
" When you submit the application to the visa office please ensure
that your certificates were not issued more than three months before you
submitted your application to the CIO
"
I think, that should be : Unique Client Identifier which is used under GCMS system. That means CIC is trying to use new management system for our application.
BTW, a question for all who revd aor: is there the "UCI" number in your mail ?