Peter writes:
(In)"Correction:
"A4 is not an international standard paper size, it is the international standard paper size."
Peter, I know there are differences between Australian English and the version(s) of English used in other parts of the world, but until reading this I thought we all agreed on the meaning of "an."
A4 is an international standard paper size.
It is one of 22 standard paper sizes defined in ISO standard 216, 11 in the A series, 11 in the B series.
Additional international standard paper sizes are defined in two supplementary standards, ISO 269 (C series, used for envelopes) and ISO 217 (RA and SRA series of raw (untrimmed) sizes.
If any of these is "the" international standard paper size, it is A0, from which all of the others are derived.
A0 is defined as a rectangular sheet with an area of 1 square metre, and an aspect ratio of 1:√2.
Each succeeding size is one half the previous size, with the division done parallel to the short edge of the larger size.
B series sizes have the same aspect ration, and are "placed at the geometric mean between adjacent sizes" in the A series. B0 has a long edge of 1m.
Regarding "the American antediluvian system," I would concur with a description of 'antiquarian,' but, considering the respective dates of the deluge and the founding (or even the naming) of America, the joining of these two adjectives is a bit of an exaggeration, to say the least. ;-)
Regards,
Barry