Strange update to perch/core/lang/en-gb.txt

Seem to be getting strange additions to the en-gb.txt lang file inside perch, as everytime I think I've committed everything to git, I'll randomly get an untracked change from this file, and it's always this file. So I'm curious if Perch is taking liberty over this file for some reason? And if this can be changed? It's incredibly annoying and I'm not even sure what it's purpose is. I felt like it was a string placeholder file for mapping text to elements, but it seems to just randomly add things, and doesn't provide any sort of shortcut mapping, as the file looks like JSON which maps a token of the same string as the actual value each token is assigned to.