I was recently chastised at work for using the word "cool" in an email chain--an act that I attribute to being overly-formal for no other reason than to uphold an unnecessarily perceived "law" of formality. Is there an English word that would better describe this?
The apt words are
a person who displays or demands of others pointlessly precise conformity, fussiness about trivialities, or exaggerated propriety, especially in a self-righteous or irritating manner.
a person who is excessively proper or modest in speech, conduct, dress, etc.
a person who overemphasizes rules or minor details.
a person who adheres rigidly to book knowledge without regard to common sense.
Stuffy comes to mind -
Rigidly adhering to standards of conduct; strait-laced
excessively dull, staid, or conventional
Perhaps prissy would suit your meaning:-
Excessively or affectedly prim and proper.
You might consider pompous
someone who is pompous thinks they are very important and speaks or behaves in a very serious and formal way
The term also carries with it the connotation of self-important that may or may not fit your circumstances.
"Formalist" could do ?
check definition here:
For more negative emphasis: "pedant"
maybe could also do.