I have no idea why, but for some reason the CAA only mentions that you have a sufficient level of English proficiency (which means 4 or higher) on your license. They don't mention the actual level or the expiration date (for levels 5 and below).
Also, there are persistent rumours that the CAA refuses to annotate your license with a Language Proficiency other than English. Which is kind of a problem since there are a lot of French-only airfields in France that require French proficiency similar to LPE.
Requiring foreign aircrew to prove that their English language skills are sufficient is a good idea in principle, especially for e.g. Russian, Indian and Chinese crews, but the way this was eventually implemented by the various authorities leaves a lot to be desired.