TeX: system's default paper size
There is a discussion going on on d-d , whether TeX should support
other paper formats as *system-wide* default for paper size, apart from
'a4paper' and 'letter'.
Does anyone on this list have a desire and/or could give some arguments,
why and where it would be useful to use a system's default different
from 'a4' or 'letter'?
(This discussion applies only to TeX/texlive and only on the system's
default. Different paper sizes can also be set on a per document basis.)
See  for further information from the DD of texlive.