[XeTeX] Problem changing default fonts

[Philip Taylor (Webmaster, Ret'd)]

Khaled Hosny wrote:

> Its \textbf{}, \textsf{} etc. (even plain TeX \bf is not a macro but a
> font CS and it to be used as {\bf Some Text}).

Sorry Khaled, \bf /is/ a macro :

> C:\Documents and Settings\Administrator>tex
> This is TeX, Version 3.1415926 (Web2C 2010)
> **\message {\meaning \bf}
> macro:->\fam \bffam \tenbf
> *

** Phil.