Adjective for being okay to send via an unreliable protocol?

UDP is an example of an unreliable protocol. Is there a single word that means "okay to send via an unreliable protocol?" Sort of like "unimportant", but that’s too strong a word.

The context would be the name of a message property where the application cares that certain messages are delivered reliably, but is otherwise agnostic about the delivery method. I’m looking for a word that means "unreliable okay" rather than "reliable required" because reliable should be the default and booleans conventionally default to false.