I'm in the similar point of view.
In addition in italian there is also an ambiguity: it could be a "manual"
or "handbook" or it could be a "perfect book" (???). which version is
correct?
In the second case what is handbook? A book like "Galateo"
(
"As a general rule, most books you might expect to find in the
non-fiction section of your local library or bookshop are not
acceptable. This is for textbooks."
This definition is not only , in my opinion, not only cumbersome,
but also open a serious question: What is a textbook?
Just as an example why a cookbook is not a textbook? In many school
cookbook are used as a textbook. Morover they are used in some small
lecture course about cooking. What should be consider as a textbook?
Just what is normally used in American High school?