Introduction to critical apparatus

Some time ago I found somewhere on the web a good introduction on how to use a critical apparatus. It was a PDF file (I think) of something like 5 or 20 pages, consisting in big part of a glossary of all the latin words and abreviations you can find a critical apparatus.

The problem is, I don’t remember where it was and I can’t find it anymore. I didn’t I bookmark it.

Could someone who knows what I mean please post a link? Thanks a lot!

This?

That’s the one, exactly! Thanks!