Missing a little explanation in RailsGuide

Hi there guys!
First of all, thank you all for the great work!
I'm in my first job with RoR and needed to make a HABTM association.
Of course, I looked in http://guides.rubyonrails.org/association_basics.html#the-has-and-belongs-to-many-association
to see how it is done and I think there is missing a little info:
I have two tables: types and users, should the join table be
types_users or users_types?
A friend of mine clarified that it's in alphabetic order, so it's
It should be explained in the guide. It's a important thing.

Thanks again for the great work,
Álan Crístoffer

It's in there. Section 3.3.2.