Re: Line Separator and Paragraph Separator

From: Frank da Cruz (
Date: Mon Oct 20 2003 - 09:52:50 CST

> Are the LS and PS characters actually used in real plain-text documents?
At some point in the early 1990s, the thinking was that ASCII control
characters were included in Unicode only for round-trip compatibility
with existing character sets, but their semantics were undefined, and anyway
they were not needed since they were from the bygone days of terminals and
similar antique contraptions, whereas in modern times all text is "flowed"
by "smart rendering engines".

Ten years hence, the terminal-to-host model is still widely used, as is text
with hard line breaks, but to convince the skeptics and ultra-modernists
that line breaks were still a useful concept, I mentioned line-oriented
programming languages (such as Fortran), and poetry. Hence the line

Later everybody realized you couldn't stamp out ASCII control characters,
so we're still using them; LS and PS never caught on as far as I know.
Although obviously, LS would have been an improvement over the existing
situation, in which different line separators (CR, LF, CRLF) are used
on different platforms, which would otherwise have compatible text
record formats, which to this day causes no end of confusion.

At some point after Unicode 2.0, the C1 controls were adopted from ISO 6429,
in which we have a Next Line control (NEL, U+0085), which might also have
served the purpose, but it never caught on either.

- Frank

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