Jon, here I am.
Which fonts are installed depends on the kind of machine.
On Windows, I think you always get Times New Roman, Arial and Courier (NOT Courier New).
On Apples, Unix-Derivates and other machines I do not know.

Usually there are more fonts installed than the 3 mentioned above, but these three are guaranteed on a Win95, Win98, WinNT and Win2000 installation.

I usually try to avoid using the <font face=...> as people have their most-loved font as their default font. And if there is no specific reason to change it, I do not do it.
Sometimes you need an unproportional font, then I use the <tt> tag to tell the browser to use its default unproportional font, not a specific one.

If you want to use the <font face=...>, you should always give at least two fonts (comma separated), where the last one should be one of the 3 mentioned above. The browser will use the first one given which it can find on the system.

If you work with CSS style sheets, you can set the font-family to one of its default values (serif, sans-serif, cursive, fantasy und monospace) for which each browser should have a font (but you don't know which one a specific browser will use, e.g. it could use Courier, Courier New or some other unproportional font for monospace).
Of course you can also use a font name like Courier New with style sheets, but then you will once again have the same problem if the font is not installed on a user's machine.

So Joe, I would suggest to use a special color (combined with bold or a headline tag (h1,... h6)) for the Mudcat Classic Threads or as Jon suggests an image file.

MudGuard (who goes to bed now)