Please consider making the *E backends lower-case the file extensions. This improves deduplication especially with image files, where cameras often use *.JPG, while other software such as the Dropbox Android app rename the images to *.jpg. We talked about that very shortly a few months ago:

(Log starts 2015-08-06 21:11:40 CET)

 tribut  is there a backend that lowercases the extension? or do the *E backends do that anyway?
 joeyh   it does not
 tribut  but would it make sense? or am i missing something?
 joeyh   I don't know.. the extension is only there for stupid programs that follow symlinks and
         check extensions. If such a program cares about .GIF vss .gif, you might have a problem
 joeyh   I think that you can git-annex migrate from hashE to hash, then migrate back, and it'll
         update to the new file extension.
 tribut  i was thinking about content-identical images with .JPG or .jpg extension
 tribut  and because even the most retarded of programs wont care, i thought the backend could
         lowercase the extension
 joeyh   ah, sure, using the E backend reduces the ability to de-duplicate
 joeyh   I'd not want to add a e backend set just for this. There's no requirement that the
         extension extraction code be stable, so it could be considered changing it to lower-case
 joeyh   otoh, I have no idea if some programs are dumb enough to care about .git vs .GIF