Proposal: Document use of control characters

Murray Maloney <>
Date: Thu, 16 Jun 94 12:20:40 EDT
Message-id: <9406161206.aa11328@dali.scocan.sco.COM>
Precedence: bulk
From: Murray Maloney <>
To: Multiple recipients of list <>
Subject: Proposal: Document use of control characters
X-Listprocessor-Version: 6.0c -- ListProcessor by Anastasios Kotsikonas
X-Comment: HTML Implementation Group

Proposal:  Identify the control characters in ISO 8859/1
that are recognized as valid HTML. identify those
control characters which are not valid by specifying
them as SHUNCHARs in the SGML declaration, and document
them in the HTML specification.  For each control character
that is valid, identify its meaning and potential uses.
For all control characters which are not valid, list
the characters and their codes, and specify the error
(if any) which may result if the character is discovered.

Some background...

The character set for ISO 8859/1 Latin alphabet No 1
includes characters from most Western European languages.
It consists of the space character, 186 characters 
that form a subset of the graphic characters 
in ISO 6937/2 (1983), and four additional characters
that are intended for inclusion in ISO 6937/2.

The standard specifically states that control characters
are beyond the scope of ISO 8859/1.  However, in practice,
reference to thsi character set includes reference
to the control characters that are specified in 
ISO 646, ISO 6429, and the ASCII character sets.

The following two characters fall within 8859/1.
Their behaviour should be specified in the standard.

	160	nbsp		no-break space
	173	shy		soft hyphen

There are also several character positions which are unassigned.

The character positions in question are (in decimal):

	132	ind		index
	133	nel		next line
	134	ssa		start of selected area
	135	esa		end of selected area
	136	hts		horizontal tab set
	137	htj		horizontal tab with justification
	138	vts		vertical tab set
	139	pld		partial line down
	140	plu		partial line up
	141	ri		reverse index
	142	ss2		single shift 2
	143	ss3		single shift 3
	144	dcs		device control string
	145	pu1		private use 1
	146	pu2		private use 2
	147	sts		set transmit state
	148	cch		cancel character
	149	mw		message waiting
	150	spa		start of guarded protected area
	151	epa		end of guarded protected area
	155	csi		control sequence character
	156	st		???
	157	osc		operating system command
	158	pm		privacy message
	159	apc		application program command