Is there a "standard" format for command line/shell help text?

If not, is there a de facto standard? Basically I'm writing a command line help text like so: usage: app_name [options] required_input required_input2 options: -a, --argument Does something -b required Does something with "required" -c, --command required Something else -d [optlistitem1 optlistitem 2 ... ] Something with list I made that from basically just reading the help text of various tools,