# [texhax] The Em Rule, a Question of Style

Tue May 18 14:55:53 CEST 2010

```P. R. Stanley wrote:
> Hi folks,
> I read somewhere that the em rule should preferably be prefixed with a
> non-breakable space character ( ~ ), mainly for stylistic reasons,
> however, there was no mention of a ~ suffix to ensure that a line break
> doesn't occur immediately after the em dash.  Would a conscientious
> typesetter place a ~ on both sides of the em dash, or a prefix ~ is the
> only stylistic requirement? Further, what would the list think of the
> idea of using \mbox to make sure that a line break doesn't appear on the
> left or either side of the em rule/
>
> Thanks
> Paul
>

ok, that requirement, I haven't heard for the em-dash, but rather for
the en-dash

To my knowledge, in English the em-dash is used without spaces, and in

blah---blah

in LaTeX code.

Whereas in Danish, we write

blah -- blah

that is with spaces and with an en-dash. I haven't heard that a
non-breaking space is needed in this case.

(My copy of the Chicago Manual of Style, is at home so I cannot look it up)

--

/daleif
```