NONCE POEM

As I understand it, the nonce poem is one in which the form (meter, rhyme, length, etc.) has been made up by the individual poet.  Other poets may admire the final product and imitate it, and so in time this new form may become an established pattern.  At the time of its creation, however, it is not a known entity, and as such should not be sent to a poetry competition requiring established formats.