[l10n, apt-git-repo] question about l10n for APT

[lumin <cdluminate@gmail.com>]

Hi,

I'm one of the current translators in the alioth APT team.
And recently I noticed a change about your usage of
APT's git repo. So I'd like to ask some questions.

Long time ago, the default branch for APT is debian/sid,
so at that time I commit the l10n updates directly to debian/sid.

However the current default branch becomes "master",
and a part of contents in debian/sid is not merged
into "master".

So I'm confused about the co-existence of
debian/exp + debian/sid  && master.

1. what are debian/exp and debian/sid used for ?
   Are they still in use ? (only master is active now)

Additionally:

2. does that mean, I should switch my working branch
   from "debian/sid" to "master" ?
3. in the past, I only change the .po files at every commit.
   can I add related debian/changelog entry by myself ?


Thanks.
:-)