In error, maybe due to a typo, the directory ends up containing a file that begins the a hyphen '-'. Other than removing the whole directory, removing a file with such a name can prove troublesome as Unix most command options are signified by the use of hyphen '-' too.
There is however a little documented Unix option that can actually negate, or switch off the use hyphens as option indicators and cause them to be treated as literal characters. It is the option hyphen, hyphen '—'.
cd mydir ls -typofile goodfile1 goodfile2 rm -typofile rm: illegal option -- t rm: illegal option -- y rm: illegal option -- p rm: illegal option -- o rm: illegal option -- l rm: illegal option -- e usage: rm [-fiRr] file ... rm -- -typofile ls goodfile1 goodfile2