Bugger. I forgot. In addition to the four mentioned bits (license, class/type rating, additional ratings, medical) there is a fifth element to your license: the Language Proficiency.
In order to obtain/maintain a valid license you have to have demonstrated a certain level of proficiency in either English or the language of the country you fly in (and is used for R/T). There are six levels defined by ICAO, from 1 (extremely poor) to 6 (fluent).
In the UK, as part of your flight test, the examiner will judge your proficiency in English. If he deems you fluent (which is pretty likely) you'll get an LPE 6 (Language Proficiency - English level 6) from him, which is valid for life. But if you're not completely fluent in English he's got to refer you to a language institute which will test and grade you further. The minimum requirement is ICAO level 4, which is valid for four years (I believe - it used to be three). ICAO level 5 is valid for six years (I believe - it used to be five), after which you'll need a retest to see if you made any progress. If you score below ICAO level 4, the CAA cannot issue you a license.
Language Proficiency is not just for English. If you want to fly to airfields that are French-only, you need at least an LPF (Language Proficiency in French) at ICAO level 4. Similar for German and so forth. Although, at the moment, I think nobody in France or Germany actually checks for this. If you don't make a complete hash of your French or German R/T (and there are plenty crib sheets available to help you) you should be fine.
So all these Language Proficiencies form an additional stack of papers to collect.
And come to think of it - in the UK there also used to be a bit of paper called the "Flight Radio Telephone Operator License" (FRTOL) which is automatically granted together with the PPL under normal circumstances, since the PPL implies you have done the theoretical and practical Comms exam, and demonstrated competent use of the radio during your test. It is also revalidated at the same interval as your PPL so you normally don't need to worry about it. I think it's a separate bit of paper since it's possible to do the FRTOL tests separately from flight training, for instance if you're going to be an A/G operator at an uncontrolled airfield. But anyway, I seem to recall that under EASA the FRTOL is simply absorbed in the PPL and no longer a separate bit of paper.