[syslinux] Allowed code pages and encodings to write f0.txt through f1.txt?

[Ady]

> (1) Which character encodings can be used in message.txt and f1.txt through f1O.txt?
 
The default in the BIOS, mainly Code Page 437
 http://en.wikipedia.org/wiki/Code_page_437 

This code covers many (most) of the characters used in Latin-derived 
scripts (alphabets), Western European countries.

In theory, in the cfg file you could potentially add a FONT directive 
and a .psf font file (see the official Syslinux package, 
.doc/syslinux.txt), but this method is very rarely used.
 
> (2) Is UTF-8 allowed?
 
Not yet.