"title" not a valid LiQL constraint

I have several categories and their titles are similar to the following

"Moderators ABC"

"Moderators XYZ"

"Moderators 123"

I attemted to access them, first by the more direct

SELECT title FROM categories WHERE title = "Moderators ABC"

and also by

SELECT title FROM categories WHERE title MATCHES "Moderators"

Both of these queries returned a 604 error that said "'title' is not a valid constraint for the object 'categories'."

Does anyone know why title might not be a valid constraint? And what I can do to select all of my Moderators categories?

Thanks!