[whatwg] Physical quantities: <var> or <i>?

[Bjartur Thorlacius]

On 4/14/11, Christoph Päper <christoph.paeper at crissov.de> wrote:
> Jukka K. Korpela:
>
>> <var>c</var> would be odd, wouldn't it, since the symbol denotes a
>> universal constant of nature.
>
> It would not, ‘c’ is merely a variable with constant value.
>
Well, a constant isn't really variable any more, is it? I thought
<var> was meant to mark up text that couldn't simply be 'copypasted'
without filling in the unknowns (free variables). Defined variables
(whether in source code or formulae) do not conform to that
definition.

So, <code>rm -r <var>$path</var></code> would conform (as a reply to
the question "how does one remove a (potentially non-empty) directory
on *nix?") as $path is undefined, but <code><var>i</var>++</code>
would not, as i isn't ment to be substituted.

>   <var>E</var> = <var>m</var>·<var>c</var><sup>2</sup>
>
> Or <math>, eventually.
Or, in the meantime, <code> (IMHO, at least). It's not source code for
a computer program, but for all purposes and intentions I can think
of, source code and formulae can be treated equivalently. The spec
formally requires 'computer code,' i.e. sth understood by a computer,
making my suggested usage non-conformant.