Re: Should vertical motions be in vees or ems? Where does the baseline go?

[Dave Kemper]

On 11/16/21, Ralph Corderoy <ralph@inputplus.co.uk> wrote:
>> > What's the argument against CSTR 54's section 11.1 definitions being
>> > the ideal?
>>
>> Two are:
>> - General typographic convention is to measure vertical motions in
>> v's, not m's.  CSTR #54's definitions of \u, \d, and \r do not align
>> with this common expectation.
>
> That shipped sailed in the Seventies.  :-)
>
>> - CSTR #54 is not even internally consistent in this regard: most
>> vertical motions are specified in v's.  \u, \d, and \r are outliers
>> even in troff-land.
>
> Ditto.

Well, I shan't pretend to know your mind, but if you ask what the
counterarguments to CSTR #54 are, then rebut those by claiming CSTR
#54 is inviolable, it rather gives the impression you didn't much care
what any counterarguments were.

The argument for following CSTR #54 is historical troff practice,
which is a fundamental consideration in the community.  But the
argument against CSTR #54 "being the ideal," which is what you asked,
is that its definitions of these three escapes are not ideal.

For the record, I'm not advocating that groff's behavior be changed;
as long as the units are clearly documented, the user has sufficient
notice that they're perhaps not what she might have expected.  And
this is far from the most significant tension between "what users
might expect" and "what troff did in the '70s."

Also, taking CSTR #54 as the holy text still doesn't address the
difference between where groff and Heirloom's baselines fall, or which
one's behavior is the more typographically sound, or what course
should be plotted if this is another case of the typographic ideal
conflicting with historical troff practice but this time without
mediation from CSTR #54.

> The analysis stops with a guess which is wrong.  I've added a comment to
> the issue:

Thank you for the clarification about this.