On 2012/9/24 Hannie Dumoleyn wrote:
[...]
 I understand what you mean, but I
 have not been clear on what the real problem is. For every new version of
 Ubuntu we rewrite/revise our manual. All translations of strings that have
 changed, even if it was only a comma, will be lost in Launchpad. My idea
 was: the smaller the msgid, the smaller the loss of translations.
 btw, with msgmerge I merged the translation file of the previous version
 (oneiric) with the new one (Precise). In Lokalize, a translation tool, the
 strings that have undergone some kind of change, are shown as Fuzzies. I
 only have to translate the small changes in these fuzzies. Working in
 Lokalize (offline) does not have the advantage of Launchpad, where more than
 one translator can work on the same file online. But working in Launchpad
 means all fuzzies from Lokalize have to be copied manually to Launchpad. 
I am paraphrasing you to be sure that I fully understand what you
mean.  I know almost nothing about Lokalize and Launchpad, so I may
get fully wrong.
So you run "msgmerge --previous" to update your latest translation
with the latest POT file.  Lokalize is smart enough to display what
has changed in fuzzy strings, and you can very quickly catch
formatting changes and update translations.  It works fine, but does
not well interact with Launchpad because you have to work offline.  Is
this what you mean?
 If nothing can be done about this, it means translators are not very
keen on
 translating long documents such as The Ubuntu Manual or the official Ubuntu
 Documentation. 
IMO this is an issue with Launchpad, it should display changes like
Lokalize to help translators.  Po4a calls msgmerge --previous since at
least version 0.40.2.
Denis