>>>>> On Fri, 13 May 2011, Michał Górny wrote:

>> > +be disabled by~user too, using a~PM-specific mechanism.
>> 
>> > +\item \t{src\_test} (except if \t{RESTRICT=test} or~disabled
>> > by~user)
>> 
>> Could you please use the ~ more sparingly? I don't see a reason why
>> line breaks at these points should be suppressed.

> The rules of typography state that prepositions should not appear at
> the end of a line.

I've consulted some typography books: The Chicago manual of style [1]
doesn't mention such a rule at all. Dowding [2] mentions it, but only
for ragged-edged columns, not for justified ones (also the book
doesn't follow such a rule for its own text).

However, the main point is that the document will be processed
automatically with very little human intervention. So we shouldn't
take away too many possible break points from TeX, otherwise we risk
uneven spacing or overfull hboxes.

> But sure I can if you can tell me when to use it.

So far, the only places where ~ is used is for cross references, i.e.
between the word "section", "table", etc., and the following number
(specified by \ref).

Ulrich

[1] The Chicago manual of style. 14th edition, Univ. of Chicago Press,
    Chicago 1993. ISBN 0-226-10389-7.
[2] Geoffrey Dowding: Finer points in the spacing & arrangement of
    type. Revised edition, Hartley & Marks, 1995. ISBN 0-88179-119-9.