Prints outside the standard edition (which are intended for the artist's private collection and used as part of the original artist-publisher agreement) are called Artist’s Proofs. More commonly they are the first run of an edition which is proofed by the artist to ensure that the edition will properly represent images and colours as intended.
The notation that this image is an Artist Proof is pencilled in at the bottom of a print as A/P, along with the title and the artists signature.
The number of Artists Proofs offered will vary among artists but this artist usually limits hers to 50.