Is there an easy way to place an order on hold?

I have an order which I can't process just yet and wanted to change the status to "on hold" so it doesn't get accidentally marked as shipped.

I know these statuses are defined as an Enum in code, so it isn't easy to add one. Can we have a new "on hold" status adding. This wouldn't form any part of the existing order process, but would allow a way to park an order if something needs sorting out on it.