Hi
What does the little yellow "open" book mean?

It means "book".

If you hover your mouse over each of the icons at the top of the posting page (if you are on PC) you will see a small box with text in it, a one word description of the icon. If you are on a MAC not certain if that function works, though.

I have no idea why most people are using that specific icon, unless it's just because it's the first one in from (blushing). Obviously, not every post it is attached to is about a book.

BTW, I love the flexibility of this forum (although just a few moments ago when I went to colour my original text, when I did so, it blew away the text I had highlighted to colour. (Good thing I have a pretty good memory.)

Cheers!
Unis

The little yellow book icon just happens to be the default icon. If you create a post you can select which icon you want to use. Same if you reply to a post using the normal reply.

Normal reply gives you access to the codes.

Quick reply which appears at the bottom of the page is great if you don't want to use, any special code. Or you can add the codes during a preview.

Alex