Sentence:  If an awarding institution cannot be identified as Scottish and the qualification is ONC/OND, HNC/HND, Clerical or Commercial, City and Guilds, Apprenticeship or a degree awarded by the C.N. A. A. boxes 1 and 2 are examined and if a Scottish school examination has been entered in either of the two boxes it is assumed that the ONC/OND, HNC/HND, Clerical or Commercial award etc. etc. is Scottish also, and the <WSD>overcode</WSD> x is entered. 
Meaning of the word marked with <WSD> tags:  A code used to represent multiple (possibly unrelated) data items.