Having done this task regularly (via Dreamweaver) for over a decade, I feel I’m an old hand when it comes to FTP‘ing. I installed the recommended GUI, FileZilla, and logged in. Upon downloading the readme.txt file I learned one of the case sensitive servers is the UNIX platform. Capitalization (or capitalisation) matters for most, but not all, servers. Play it safe, as always, and be consistent with yourself at least. I’m a lower-case man myself, so I’ll never name files like ReadMe.txt or anything using capital letters. People have gotten used typing all lower-case in both URLs and email addresses. The worst case scenario is actually worse than the user getting a 404 File Not Found - they could end up on an old version of your page before you started with your convention. Play it safe.