To me, that means one gets a new licence - "wishes to obtain a National Private Pilots Licence..." - which is different from adding a rating to another type of licence!
It was issued as a AIC a while back and is now embedded in the ANO.
ANO Schedule 7 Part B
Section 2 – Aircraft and instructor ratings which may be included in United Kingdom aeroplane pilot licences and in National Private Pilot’s Licences (Aeroplanes)
The following ratings may be included in a United Kingdom aeroplane pilot licence or a National Private Pilot’s Licence (Aeroplanes) granted under Part 7, and, subject to the provisions of this Order and of the licence, the inclusion of a rating in a licence has the consequences specified as follows.
Microlight Class Rating
...
SSEA class rating
...
SLMG class rating
...
xrayalpha, I understand you specialise in microlights: have a look also at CAP 804, Section 5 Part A, Subpart 2 Page 7, para 3.13.
ifitaint...