There are numerate people who have limited experience in interpreting the algebra used in computer science papers. Therefore, it would be most useful if there were a list of all algebraic symbols used in the Yellow Paper, along with their definition as applied in the paper.
There is of couse this guide, however, for some of the symbols, there are multiple interpretaions.
Please list the symbols used and define their meaning. My understanding is as in my answer below. I've used bold italics where I'm particularly unsure. Please point out where I am wrong.
EDIT - I've posted the list as a community wiki.