Missing Chapters in TGM (or not?)

I have noticed in my TGM book, the following chapters are missing:

1-I
2-I
2-Q
6-I

There are chapters before and after (e.g 1-H and 1-J, 2-P and 2-R) but not the ones
listed above.

Is this deliberate and why?

My only guess is that with certain typefaces the letter I and the number 1 might look similar thus adding to unnecessary confusion. The Q might appear as a zero.