I like the cheat sheet. As far as adding it to the distribution, I think it is a good idea. I think a better name for it is 'quick reference guide'.

I was unable to get a clean text formatted version of the sheet from your web site. Cut-and-paste brought weird characters in, and the 'view source' version has escaped characters.

For content, I would like more about exists, defined, keys, values, and ref.

For typography, I think a PDF would be a great addition! A PDF could hold more information. I would like a PDF that could be rendered into a little four-page booklet, created by folding a double-sided printout. Those of us without young eyes could print on two double-sided sheets, or use bigger paper. A narrow version suitable for taping to the side of a monitor would be a true 'cheat sheet'.

A PDF version with various page layouts would make a great addition to the test suite of the PDF generation modules.

It should work perfectly the first time! - toma