Change bars (Thomas R. Bruce)
From: (Thomas R. Bruce)
Message-id: <>
Subject: Change bars
Date: Fri, 6 Aug 1993 07:27:06 -0400
X-Mailer: ELM [version 2.2 PL15]
Status: RO

As those of you who were in Cambridge know, I am mildly obsessive on
the subject of change bars in the new HTML spec.  The root of that
obsession is the need for legal people to compare successive versions
of texts (say, for laughs, the tax laws) to determine what, if any,
effects amendments will have/have had.  Note that this is not the same as
needing the "version currently in force", which is what you would want
in a man page, for example.  Both versions are needed for comparison

Traditionally, of course, this is done by the so-called
"redline/strikeout" method in which the old version is rendered in one
way and the new version in another, somewhat interleaved.  
Generally this is done in a way
slightly more comprehensible than a diff-generated text, though the
granularity of comparisons varies widely depending on what software or
human means is used to do it.

The short version:

   A change bar spec which only shows the current version is, by
itself, inadequate for our purposes and probably for any discipline
where revision/versioning is important beyond needing to know only
_that_ something has changed rather than _how_ it has changed.
  At the risk of drawing a rain of fire on my head I would suggest
that one solution would be <em strikeout> or some such in conjunction
with the existing spec.

  It may also be worth thinking about the extensibility of whatever
this ends up being...since it seems like a fundamental piece of a
collaborative editing environment for text.

|  Thomas R. Bruce          |
|  Research Associate                                         |
|  Cornell Law School                     Voice: 607-255-1221 |
|  Myron Taylor Hall                        FAX: 607-255-7193 |
|  Ithaca, NY 14853                                           |