Non-breaking spaces

It is important to distinguish the precise issue at hand, that is to say
the acceptability, or otherwise, of <img href="imagefile" alt="&nbsp;">
and the more general desire to avoid misuses of the non-breaking space as
such.

On the first point, it was broadly accepted at today's teleconference that
the use of images to control spacing should be discouraged as poor
practice, as it violates the distinction between content (the image) and
style (the spatial layout of the text). Rather, style sheets should be
used for such purposes. Beyond this, I suggested, and it seems to have
been accepted, that ALT="&nbsp;" does not have any particular problems of
its own, but that it should nonetheless be flagged as an error, as it
indicates lack of attention to guideline 3. However, it is not as serious
an error as ALT=" ", since the latter may be misinterpreted by user
agents, as the discussion of "white space" in the HTML 4.0 specification
makes clear.

As to the more general abuse of non-breaking spaces, one serious
accessibility effect that it may have occurs in the case of braille. It is
perfectly reasonable to implement a braille translator so that it will
honour non-breaking spaces (indeed, I believe that most widely used
translators include this feature in their proprietary formatting schemes).
In braille, except where indentation is concerned (and the latter is
generally subject to spatial constraints not found in print), multiple
spaces are usually suppressed. Thus, misuse of non-breaking spaces would
often result in spurious space appearing partway through a braille line,
hardly a desirable outcome from the perspective of braille formatting.

Thus I would suggest that in any discussion of this subject in the
Techniques document, such practices ought to be discouraged (and likewise
as regards validation tools), but that the ER proposal (ALT="&nbsp;") need
not be disallowed antlogether.

Received on Friday, 29 October 1999 05:08:21 UTC