The conventions for numbering prints are well-established, a limited edition is normally hand signed and numbered by the artist, typically in pencil, in the form (e.g.): 14/100. The first number is the number of the print itself. The second number is the number of overall prints the artist will print of that image. The lower the second number is, the more valuable and collectible the limited editions are likely to be, within whatever their price range is. Other marks may indicate that a print has been made in addition to the numbered prints of an edition. Artist's proofs are marked "A. P." or "P/A", sometimes E. A. or E. d'A. (épreuve d'artiste); monoprints and uniquely hand-altered prints are marked "unique"; prints that are given to someone or are for some reason unsuitable for sale are marked "H. C." or "H/C", meaning "hors de commerce", not for sale. These are usually prints reserved for the publisher, like Artist's Proofs. The printer is also often allowed to retain some proof impressions; these are marked "P. P." Finally, a master image may be printed against which the members of the edition are compared for quality: these are marked as "bon à tirer" or "BAT" ("good to print" in French). In all, the number of the main edition can represent 50% or less of the total number of good impressions taken.