-aOutput all.
-c argOutput just arg.
--longOutput all day long.
/VA VMS/DOS-style option.
-pThis option has two paragraphs in the description. This is the first.
This is the second. Blank lines may be omitted between options (as above) or left in (as here and below).
--very-long-optionA VMS-style option. Note the adjustment for the required two spaces.
--an-even-longer-optionThe description can also start on the next line.
-2, --twoThis option has two variants.
-f FILE, --file=FILEThese two options are synonyms; both have arguments.
-f <[path]file>Option argument placeholders must start with a letter or be wrapped in angle brackets.
-d <src dest>Angle brackets are also required if an option expects more than one argument.