Another thing that annoys me about a lot of manuals in general is how they will feature a page of "Abbreviations Found In This Manual" and this list contains about 10 entries (some of which NEVER actually come up in the book).
And then the book is chock full of unexplained abbreviations which defy you to decode them.
For example, I see 5 pins listed on the ECU diagram as AVCC or AVCC2.
No where in the book can I find any decoding of that abbreviation.
I have even tried web searching the term but come up empty headed.
I believe that technical publications are by law compiled by dozens of separate committees that have no communication with each other ( and probably don't even know there are others besides their group) and simply submit the chapter they were assigned to do.
Then the lot is tossed into a barrel and sent to the printer (all except a few pages which are lost along the way, also required by law) :^)