When people take the time to help out with the localisation at translatewiki.net, it is really important for us that this time is spend has a high impact. The other day Siebrand was happy to tell me that when you are localising a message, you can go to the messages for a particular extension. I did not get it. Now I do.
When you start from the language stats for a language like in this example for Welsh, you can select the "MediaWiki extensions used by Wikimedia". This gives you a list of messages that are not sorted in any way and consequently the localisations do not have the impact they could have.
The novelty is that once a message is selected, it is now possible to continue with the other messages for the same extension. Localising messages for the same extension has a much higher impact because a user is likely to find them together.