13:44 Sep 27 

Thank you to Peter and Lipabel, Lawyer-Linguist and Bruce for all your input. In the end I am just going to close it without awarding any points because the police gave me the answer. Really grateful to all of you though for taking the time to contribute some feedback.

16:55 Sep 4 

I'm sorry, but Writeaway is right away with the fairies if he/she thinks this is non-pro! A very specific meaning of an apparently but deceptively obvious phrase, asked by a pro translator, MUST be PRO.

16:29 Sep 4 

According to the rules, the term doesn't qualify as a non-pro question. Apart from that, 'akte' can be translated in a number of different ways, as your question has clearly shown. I'm sure a number of people will find your glossary entry useful in this particular context once you close the question. It's sometimes the simplest looking of terms that can trip us up -- this question is a good example of that. Looks simple, but isn't necessarily so.

16:14 Sep 4 

Forgive me for being touchy but please can Writeaway explain why this needs reclassification as non-pro?

16:12 Sep 4 

Really interested to see exactly why Writeaway thinks that this is worth reclassifying as "non-pro" - yet again.....! Is there a special dictionary she has access to explaining that an "Aktenummer" is either a "file number" or of-course-silly-old-me a special number in a licence issued to one and only one particular rank of Dutch Police Officers"? How could I be so dense?? I am fearfully sorry for bothering "pro" translators with such a basic question and will keep myself to non-pro questions in the future unless I have something of more Copernican scope.
Sorry but this happens pretty much every time I post a question. Did anyone else find the question that basic as a matter of interest? I would hardly have posted it if it was a straightforward "file number" would I... Come on Writeaway, in the words of the song "you can tell your reasons but I won't change my feelings"

15:55 Sep 4 

In the end I rang up the Dutch police and they told me that the aktenummer is a special "licence number" issued to a buitengewoon opsporingsambtenaar - thank you to both Peter and Lipabel for your input. In the end I translated it as "authorisation number"