Comment 3 for bug 1470051

From API perspective, I think we don't need to have two values which have the same meaning.
What is the difference between None and "any"?
If they mean the same, when the field is unspecified in a create request,
what value should the neutron server return, None or "any"?
If "any" is specified, should we return either of None or "any"?
In the REST principal, a value in a request and a response should match when it is specified in a request.

IMHO, None is widely used to mean unspecified and in a security group rule (or firewal rule) it sounds natural that "unspecified" means "any".

I know there are various opinions on this and suggest to discuss this in the API WG.

CLI option is different. I think it should be more descriptive, so it sounds reasonable to display "any" in the help message.