The engine normally handles strings as utf8 characters (mbcs).
The preliminary header of a pbo contains strings such as prefix, product and version (or any other).
Cyrillic characters eg are wrongly interpreted as sbcs. The 'local' codepage eg cp1252 is assumed. The result can be seen in the game's (dot)rpt file
Similarly characters > 127 are also assumed to be 'local'.
Thus version cwr³ is displayed as cwr³ and
version=ΓΦβϗΨ becomes ΓΦβϗΨ
'version' is not the issue, it is simply illustrative of what's seen in the (dot)rpt