Every character has a story: U+213a (rotated Q) (2005)

栏目: IT技术 · 发布时间: 4年前

内容简介：This article will be the first in an occasional recurring series of articles that point out little-known historical character stories in Unicode.The character in question is U+213a, ROTATED CAPITAL Q. It is a Capital Q turned 90° counter-clockwise. It is e

This article will be the first in an occasional recurring series of articles that point out little-known historical character stories in Unicode.

The character in question is U+213a, ROTATED CAPITAL Q. It is a Capital Q turned 90° counter-clockwise. It is encoded in theLetterlike Symbols block in Unicode, and according to the Unicode annotation, it is "a binding signature mark."

I am sure I am not the only one who had no flipping clue what that means.

Thankfully, Ken Whistler provided the explanation.

The proximate cause for the encoding of this character was the need to provide roundtrip mapping for encoded characters in ISO 5426-2:1996, Information and documentation -- Extension of the Latin alphabet coded character set for bibliographic information interchange -- Part 2: Latin characters used in minor European languages and obsolete typography.

That standard has four characters annotated as "Used as a binding signature mark":

0x32 REFERENCE MARK
0x34 MALTESE CROSS
0x36 RIGHTWARDS LEAF ARROW
0x37 LATIN CAPITAL LETTER SIDEWAYS Q

The first three were unified with the existing Unicode characters:

U+203B REFERENCE MARK
U+2720 MALTESE CROSS
U+2767 ROTATED FLORAL HEART BULLET (aka "hedera" or "ivy leaf")

The sideways Q could not be unified with any existing character, and so was encoded as a new character.

Binding signature marks are marks placed by publishers on the edges of signatures (aka "gatherings" -- printed and folded sheets in units of 8, 12, 16, 24, or 32 pages) for book binding.

There are a rather large number of these, which could be considered publisher logos, in a way, except that many of them make use of odd symbols available in their printers' type sets.

There is no particular need to go out and catalog more of them and encode them as characters, because of their peculiar usage not part of regular text.

However, the ROTATED CAPITAL Q got in as part of the mapping project to help get ISO TC46 out of the business of developing and maintaining character encoding standards independently of the ongoing work in ISO JTC1/SC2/WG2 to develop ISO/IEC 10646.

There you have it -- the character was encoded for compatibility with another standard that we wanted to help move on to other things and not keep encoding characters independent of Unicode. A necessary tax that we sometimes have to pay for having a universal character encoding standard.

This post brought to you by " ℺"
(U+213a, a.k.a. ROTATED CAPITAL Q)
(You may not be able to see this character unless you have a font like Code2000 that contains it)

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