$ perl -e'require "MAS::Global";'     # Bad
Can't locate MAS::Global in @INC [...] at -e line 1.

$ perl -e'require MAS::Global;'       # Ok
Can't locate MAS/Global.pm in @INC [...] at -e line 1.

$ perl -e'require "MAS/Global.pm";'   # Ok
Can't locate MAS/Global.pm in @INC [...] at -e line 1.