[css3-gcpm] Spacing and alignment of leaders

Forgive me if I am missing something (just getting started with CSS
3), but <http://www.w3.org/TR/2007/WD-css3-gcpm-20070504/#leaders>
does not seem to specify a method for horizontal spacing and alignment
of leaders. The section as now drafted seems to contemplate leaders
without horizontal spacing and alignment.

If correct, this repeats a visually ugly custom enforced by desktop
word processors (e.g., an unbroken string of repeated periods) that is
at odds with the typographical tradition of spacing between leader
characters and each leader character's alignment with the
corresponding leader character in other table of content entries. The
ugliness stems from the visual heaviness of an unbroken string of
leader characters, e.g.,
................................................

In the hot type days, leader characters were normally separated using
em and/or en spaces, and aligned horizontally. Numerals correspond in
width to an en space, so if one has a variable page number length,
e.g., pages 101, 89, and 5, the leader ending can be uniform; e.g.,
assuming that variable justification is applied between Text and the
leaders, that dot leaders are separated by one em space, and that one
en space is desired between the last leader character and the longest
page number:

Text .[em].[em].[em][en]5
Text .[em].[em].[em]89
Text .[em].[em].[en]101

produces right-aligned page numbers, a uniform gutter between the page
numbers and the leaders, and horizontally aligned
leaders. See Space Characters in Unicode,
<http://www.cs.tut.fi/~jkorpela/chars/spaces.html>.

A similar effect might be programmatically attained using tab
settings. However, it is the effect that is important, not the
methodology. Horizontally separated and aligned leaders, being less
visually overpowering, emphasize the text on the same line while still
providing the desired visual guide to the correct page number on the
right margin.

Best regards,

Paul E. Merrell, J.D. (Marbux)

-- 
Universal Interoperability Council
<http:www.universal-interop-council.org>

Received on Friday, 8 August 2008 04:13:18 UTC