We received the following question from a customer earlier today.  The question was something that many people are curious about so we’ve posted both the question and the answer below. 

Q – Is there any way to keep a space from changing to “%20” or “#” from changing to “%23” in a file name that’s being uploaded to MDO through web folders or in the Public Folder?

A – The short answer is “No”, and there are other special characters as well.
Using web folders means each file has to have a web URL and web URLs cannot include certain characters because they are used in HTML itself. “#” is one. Also blanks are not allowed. When a file name includes one of these characters they get replaced with an “escape” character which will start with % and a 2-digit code (%23 = # %20 = blank).
This is a web/internet thing, not a My Docs Online thing. All you can do is avoid using them in file names.
Here is a complete list (many of them aren’t allowed in filenames in any case):
Table of URL Escape Characters
Character Escape Character Character Escape Character
Space %20 # %23
$ %24 % %25
& %26 @ %40
%60 / %2F
: %3A ; %3B
< %3C = %3D
> %3E ? %3F
[ %5B %5C
] %5D ^ %5E
{ %7B | %7C
} %7D ~ %7E