A couple years ago I recommended using fake msgid’s in .po files and was, predictably, met with some argument. I suggested using this hack because there wasn’t a standard way to store context in a .po file yet.
Since that time msgctxt has become a standard part of gettext and makes my substitution string recommendation obsolete. I wanted to officially come out and say: substitution strings are a pain. The scripts we used made it manageable but finding strings in the code meant searching through the .po and not only was this painful for our developers but I think it confused contributors as well.
In our latest release, we’ve converted AMO to use regular .po files now. On the off chance someone followed my advice and would like to convert their site to regular .po files as well, Zbigniew Braniecki wrote a bit about the process and you can grab his scripts (and read about the troubles I had) at bug 501988.
Since I tagged this post hindsight I guess I should look back and conclude something too. Would I do it again? At the time, there were no great alternatives. So, yeah, I would get more opinions on whether the Gnome/KDE method was better, but I would do it again. I think it was the best choice out of several poor ones, but that doesn’t mean I’m not very happy to be rid of them.
 To be fair, there was a more common way, used by some KDE and Gnome projects, which was to put a delimiter in the msgid and keep the context on one side and the original string on the other. This is also pretty hacky and you can read about Gnome’s migration away from that method if you’re curious.