If you try to work with filenames that start with - (dash) such as "-filename.ext", you will get errors such as:
svn: invalid option character: i
Type 'svn help' for usage.
After some looking around, the solution for it was, instead of:
svn rm -filename.ext
To pass '--' as the first argument:
svn rm -- -filename.ext
Hope it helps anyone out there.