Punctuation was a series of markings used in various languages to improve understanding and interpretation of written sentences.
Starfleet protocol had rules for punctuation. In 2372, Tom Paris was taken to task by his senior officer, Lieutenant Rollins for not properly punctuating a conn report according to protocol. (VOY: "Investigations")
In 2373, Nog edited Jake Sisko's story Past Prologue for grammar and punctuation. (DS9: "The Ascent")