Fonts & Character Sets ⇒ Is there a table of Font codes or a way to get the code

[John_FTex]

When I use the statement \font\myfont=cmr12 at 42 pt it presumes that I know the font cmr12.

The problem is I don't know how to refer to many of the other fonts? How can I figure out the code to use?

And how can I figure out what fonts Latex can use - I guess the format font command will help on the menu. Might be an obvious question but I don't see the code, eg. the above font is Computer Modern but how does cmr12 give me the idea that it's Computer Modern?

I guess the Format Font command is for the font I'm using to type the Latex script which has not a lot to do with my document I'm creating.

This link?
https://tex.stackexchange.com/questions ... y-document

I think I found what I was looking for at this link below:
https://tug.org/FontCatalogue/

I'm wondering though, when I use the commands
\usepackage{DejaVuSerif}
\userpackage[T1]{fontenc}
why can it not find that font when it's right in the usr/share/fonts on my Linux machine?

I have switched back to the default font - Computer Modern because it's better for math.