L2/02-278
Proposal to add a VERTICAL LINE EXTENSION character
Eric Muller, Adobe Systems Inc.
July 30, 2002
Document History
Unicode includes U+23AF HORIZONTAL LINE EXTENSION. This
character is documented as: “used for extension of
arrows.” Looking for a similar character for vertical use
yields a few candidates, but they are all unsatisfactory:
-
U+007C VERTICAL LINE has a deep heritage from
ASCII. This character is used in source code of programming
languages, which makes it unlikely that a good glyph for it
would also be a good glyph for our purpose.
-
the symbols pieces (U+239C, U+239F, U+23A2, U+23A5,
U+23AA U+23AE) are intended and documented to be used in
combination with the other pieces. Furthermore, their stem
width will match those of other pieces and are not likely to
match the stem width of vertical arrows.
-
U+23B8 LEFT VERTICAL BOX LINE and U+23B9 RIGHT VERTICAL
BOX LINE are part of a “Terminal graphic
characters” group.
-
U+2758 LIGHT VERTICAL BAR, U+2759 MEDIUM VERTICAL BAR
and U+275A HEAVY VERTICAL BAR are similarly inadequate, based
on their heritage from the Dingbats font.
The proposal is to encode a new character, named VERTICAL LINE
EXTENSION. Its properties should be those of HORIZONTAL LINE
EXTENSION:
-
general category Sm
-
canonical combining class 0
-
bidirectional category ON
-
no decomposition mapping
-
no numeric value
-
not mirrored
-
no case mapping
Document History
Author: Eric
Muller
| Revision | Date | Comments |
| 1 | July 30, 2002 | First version |