As other commenters said, what you describe could actually be considered a secret code.

But in the specific german case, the code is not even that secret. This is a formal document with a very specific structure, and very standardized phrases. There is even specific software to generate the text out of performance ratings. Basically something like this:

- John was overal engaged: he is a lazy bastard

- John was engaged: he is OK

- john was very engaged: he is good

- john was always very and thoroughly engaged: he is very good