After the size of the light, it says TTO. What does that mean, please? Example below
Here is a link that might be useful: TTO
I have no idea and neither does google. Try the contact
page on the website they do email.
?? To the outside?? I'm sure the last number is "extension" or how far it sticks out from the wall.
Probably "top to outlet". It still doesn't specify whether that's the top of the backplate (or the top of the fixture) to the center of the outlet, but you can always call to clarify.