The use of a regular machine, in conjunction with one of irregular gauge, might produce, say, "perforated 14" (horizontally) "× 12 to 15" (vertically); and so on.
Stamps perforated, horizontally and vertically, by differently gauged machines are sometimes said to be "perforated, compound of ... and ...". There are many difficulties in the way of obtaining a full knowledge of the combinations and vagaries of perforating-machines.
Perforation-gauge.—A means of measuring perforation or roulette, which see.
Philatelic.—The adjective of Philately.
Philatelist.—One who studies stamps.
Philately—from two Greek words, "φίλος" (= fond of) and "ἀτέλεια" (= exemption from tax)—signifies a fondness for things (viz., stamps) which denote an exemption from tax, i.e., that the tax, or postage, has been paid. The word is a little far-fetched to imply the study of stamps, but as "Philately" has been the accepted term for over forty years, "Philately" it will doubtless remain, even if some one succeeds in finding a word which more accurately expresses the popular and scientific hobby.
Pin-perforated.—See Percé.
Plate is the term used, not always quite correctly, to describe the ultimate reproductions from the die which constitute the printing surface in the manufacture of stamps: the word covers not only a sheet of metal with stamps engraved on it, but also a group of clichés or a forme of printer's type and even a lithographic stone.
Plate number is the consecutive number of each plate of a particular value, appearing on the margin of the plates and (in some of the British series) on the stamps themselves.
Postal-fiscal is a fiscal stamp the use of which for postal purposes has been duly authorised, in contradistinction to a "fiscal postally used," a use which has been tacitly permitted in many countries.