(written from a Production point of view)
Referenced in the first draft script of ENT: "Shadows of P'Jem" (which was written while the episode had the working title "Untitled Andorians Return"), Ensign Stiles was an officer serving aboard Enterprise NX-01 in 2151.
In the aforementioned script, Stiles was referred to only once, in Sub-Commander T'Pol's dialogue. She planned to ask him to complete scans of the Argelius sector, as she couldn't finish them herself because she would be absent. In the episode's final draft script and final edit, this reference to Ensign Stiles instead became a reference to Ensign Mayweather.