The help text for the spell Deodorize says "Lessons chance of being detected by smell," almost verbatim the text for Invisible and Sneak. Additionally, "Detects by smell" is an option for the auto-translator feature, much like "Detects low HP" and "Detects spellcasting."
However, nothing in the game has ever actually detected by smell. At best, some monsters track by smell.
The help text for Deodorize should be changed to reflect the difference from Sneak and Invisible, and the Auto-translate option could easily be replaced outright by something more useful, such as "Detects abilities."