Hi, i am not sure is it a typo, but shouldn't be ellipsis after OPTION in cat synopsis https://www.gnu.org/software/coreutils/manual/coreutils.html#cat-invocation ?
I asked before on (https://unix.stackexchange.com/questions/796402/should-my-cat-utility-support-multiple-keys-simultaneously# ) and they say : "The synopsis in the GNU manual feels like an oversight — the man page synopsis comes from GNU cat’s --help option, maintained by the same people, and most other commands in the GNU coreutils manual (tac etc.) do include an ellipsis. 
– 
Stephen Kitt
 ". 
So is it a type or not?