[gentoo-user] Acceptable character encodings for files in /etc/portage?

[P Levine]

Glep 31 states that text files in the portage tree should use UTF-8
encoding.  I see nothing indicating any standard encoding for files in the
/etc/portage directory.  Since everything I have seen in portage's python
source-code seems to imply Unicode as valid but I can see nothing specific
to UTF-8, I thought I'd ask.  Is there any official Gentoo standard
documentation that defines the acceptable set of character encodings for
files in /etc/portage?