The current reputation value (rep) of StackOverflow (SO) users is mostly shown in a short form beside their name on all possible occasions. I see values like
456k. Just out of interest: what abbreviation rule works behind it?
I found a partial answer on this question What reputation is needed to get the k? which leads to the conclusion that after 9,999 follows 10k, but that's just a guess, since 10,0k would also make sense, i.e. it's not clear how many digits will be shown and how/if rounding is involved (or truncating).
I think a tiny comment added to some help page should describe how the rep value is actually formatted in the SO pages?