Question: Is there a way to control the order in which files appear in a gist? They don't seem to be alphabetical or chronological. I'd like to have a README.md appear as the first file in [a multi-file gist](https://gist.github.com/Sinetheta/6003037), but no amount of "deleting" a file and re-adding it seems to change anything.

Is there an order to these files that I'm not seeing, or does GitHub maintain an internal filetype priority list?

Answer: 
Updating my answer from an earlier year with additional testing I did just now:

Github automatically sorts files in a gist according to:

1. `#`
2. `$`
3. `.` (period)
4. Numbers
5. `_` (underscore)
6. Letters (case insensitive)

Leading spaces are dropped.

If additional characters' sort order is discovered, feel free to edit this answer.

(Added this answer because even after I improved another answer to this question last year, I still couldn't find the sort order of special characters anywhere.)
As mentioned by @VonC in his answer, the order is asciibetical. Quick solution would be to prefix all files with numbers indicating the order in which you wish the files to appear, example 0\_, 1\_, 2\_, ... 9\_. Note, this solution will not work beyond 9 files as 10\_ will appear before 2\_. In that case, two digits need to be used 00\_, 01\_, 02\_, ..., 09\_, 10\_, 11\_, ... This can be generalized to any number of digits in the number of files. Although, it seems less likely, to me, that more more than 10 files to be shared in a gist.