@jswinden: Err, according the the tests meme did on the K3, and I did on the Touch for the Kindle Collections plugin, a leading dot was always sorted more or less randomly.
Code:
# Kindle ignores these characters and sorts them randomly (unless name is only invisible characters:!
SORT_INVISIBLE = '-?/]#.\'\\*})&:@%;"!,' # means the visible are " _`^~'([{$+<=>|" + 0-9, a-z
# And on the Touch... Didn't care to test the 1 char invisible stuff, so the order might not be completely accurate...
TOUCH_SORT_INVISIBLE = ' #[:?)\\"{.!/%…;&]},*\'(@'
# Sort order for all chars (invisible needed in case the collection is 1 char long)
SORT_CHARACTERS = '- _,;:!?/.`^~\'"()[]{}@$*&#%+<=>|0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
# And on the Touch... (Note that you shouldn't be able to put a leading/trailing whitespace in a collection name, be it via the default UI or Collections Manager, that's why I put it in the invisible list on the Touch).
TOUCH_SORT_CHARACTERS = '_-`^§©®+<=>¬|~˘$ŁĄ€0123456789 abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ#[:·?)\\"{.!/%…;&]},*\'(@'
FWIW, I'm using ~ on the K3 for my 'Currently Reading' collection (=> '~Reading~'), and - the Touch (=> '-Reading-'), and it works pretty well.