TangoCMS

I don't really get what #67 is about. I also don't know what i18n support means, sorry.
But yes, There maybe examples for some strings in the language files but they should also be editable in the backend/adminCP - that's my point. So I can choose my own formulation for these strings. Especially when languages have two different words for the 'formal you' and the 'informal you' like German and Dutch.
(possible problem here/solution: there could be a 'reset' button next to a textbox that allows editing a text that is also present in a language file. This button could reset the string to the language files default value. And another button in the language settings to replace all concerned strings at once, e. g. when you changed the language.)
And in addition I think this would be useful if a language file for a certain language doesn't exist so far or its translation isn't finished yet. Then you can do it easily on your own.

...now that I really think about it it doesn't seem that easy. But what I think is the language file should change the backends language, but the language and formulation of the frontend how visiters see the web site should be the choice and work of the site's admin. A problem may be the strings that are used on both sides or the ones having a complex structure like "published by , _ ago". But what definitely should be changeable are strings like "Simple Profile", "Article Headlines", ("Welcome back, __!" - also a more complex one - maybe solvable by using variables in the backend), "My Profile", "Log out" etc. And also field titles ("Your Email Address") and in the users profiles etc.

I hope this is feasible somehow. But something like that would be nice.

#67 is about providing a translatable interface. Currently we only have GB English, however once #67 is fully implemented (it already is, really) then you can change the interface language to German, for example.

This is similar to what you're after, but from what I can see you want a second stage after this, to tweak the selected language further. So you start with 'German' and edit a few strings of the 'German' language.

As for formal/informal, these would be 2 different languages that can be selected (as part of #67). The more complex strings like you said, is actually very easy and already done. In the code it looks something like 'Published %1$s by %2$s in %3$s', so all a translate does is keep the '%1$s' within the string.

Edit: Btw, for the 'Article Headlines' in the sidebar, this can be changed by going to the Content Layout module, edit the 'main-default' layout and click 'Edit' next to the 'article' module. You should see a place to select a title, with the option of a custom one.

Ah, now I see. Yes, I'm searching for the possibility to tweak the language further.

Thanks for the tip with the article header. This would also be another idea for that language file strings. What about a drop down box like that with "default (from language file)" and "Custom...". That would also do it - if it isn't even the better solution.

And will it also be possible to edit these strings including %1$s in the backend? If yes, I think there should be an explanation that tells what's the meaning of which variable.