Minor refactoring in wysiweb

I have just forked the repo and I am familiarizing myself with the code. As part of that I have been refactoring as I go. One question I had regarding the 'wysiweb' code was about the special case of the '.' and '_' characters. Are these being used to indicate hidden files/directories? I am familiar with the use of  the period on linux but not the underscore. If they are being used for this I am intending to make that a named class variable and some documentation to indicate that but I wanted to check first.