Fat Android filenames

Works on Linux, breaks on Android

I have encountered the problem when I tried to Syncthing music between my PC and my Xperia. (Why do I mention Xperia explicitly instead of just calling it a smartphone? Because Sony is not hostile towards its customers and puts the 3.5mm audio jack on Xperias. I think it deserves the extra word-of-mouth recognition.)

The problematic files were the 04:00 track by J.R. Kensington, and everything from A.J.K.S. (notice the dot at the end).

What is so bad about the colon and the dot?

In theory, nothing. Linux filesystems handle them just fine. The problem is the fact that Android formats the SD cards using the FAT filesystem (for compatibility with Windows), and the FAT filesystem disallows them.

The colon (:) is probably disallowed because of the disk prefixes eg, C: on Windows.

The dot (.), curiously, is only disallowed at the end of a file's name. I do not know why.