The language proficiency requirement does not apply to the NPPL.
Looks like it might be a CAA ****up (error).
The requirement only applies to ICAO licences where a radio licence is held e.g. if you had a UK or JAR licence but no radio licence it would also not apply.
Quote from the official document -
"The new requirements come into effect from 5 March 2008 at which time all those intending to operate or control international flights must have the licence endorsement. This includes private pilots operating outside controlled airspace , but excludes NPPL holders."
also
"Please note: Language proficiency only applies where a Radio Licence is held."
Might be worth asking the CAA as to why they have issued you with the endorsement as you say you have an NPPL which is excluded from the requirement.
HOWEVER was your old PPL originally issued in the days before the medical reference number was introduced? If "yes" that might explain why the numbers do not corrrespond and , in fact, the endorsement is applicable to your PPL although the number on your original documents has never been revised since its original issue.
Last edited by jgs43; 26th March 2008 at 22:43.
Reason: spelling correction