PDF Only Supplements

I was thinking about what I'd like in a PDF-only supplement, the kind that's never intended to be sold as a printed book. How could you take advantage of the electronic and user-printable nature of PDF?

Let's leave off the bookmarks, because those should always be there. The only time they might not is when the content is less than four pages. We also assume that end users can print material from the PDF.

First, every character write-up on a separate page so they can be printed and used directly, without having. That means that the design of the write-ups is useful at the table as well as pretty.

A reasonably-sized graphic of a character that doesn't give away the secret ID (if there is one), so you can show the players, "Hey, he looks like this."

In fact, if the same write up had space so that you could annotate it (and the PDF allowed it), that would be great.

Cross-links between write-ups and mentions of the character. If clicking on the character's name took you to the write-up, that would be nice.

Certainly there's JavaScript stuff you could add that would make it interesting...a die roller, for instance, if there are random selection charts, that highlights the rolled entry or shades (not obscures) the other entries if you want to use the PDF directly from your tablet. (Actually, if you still want to keep the page count down in case you might print it, you can add a Print button to each character write-up that prints only that writeup, so the user could choose to print only the top character or the bottom one.)

Maps on the page would be nice: a way to print maps automagically, or to print only certain layers of maps so that the GM could plunk down the map before destruction and later after destruction.

Other ideas?