Opinions on in-band variation signaling
pagaltzis at gmx.de
Tue Nov 11 19:52:10 EST 2014
* Sean Leonard <dev+ietf at seantek.com> [2014-11-12 00:50]:
> At least one commentator (Larry Masinter) specifically requested that
> the variant identifier be included in-band in the Markdown content,
> rather than as part of the metadata. I disagree with in-band signaling
> (as has been registered earlier on this list).
Both have value.
The accuracy of metadata is inversely proportional to the
square of the distance between the data and the metadata.
That is to say, a value signalled in-band will be correct much more
often than one signalled via MIME/HTTP headers.
Also, in-band vs out-of-band simply address different scenarios.
An in-band signal travels with the data automatically, without any
special measures taken, whereas out-of-band metadata has a fair chance
of getting lost somewhere in transit. How is a user agent supposed to
store the variant parameter from the content-type after downloading
a Markdown file to disk?
But if you want to make decisions about the data during transit, having
to parse the payload to find the signal is prohibitively expensive. An
out-of-band signal is cheap, and is visible to a lot of infrastructure
that would never implement such specialised parsing of payloads such as
Markdown. (I mean, that is the exact same reason for having a MIME type
separate from text/plain in the first place.)
It’s nonsensical to portray this as a binary choice between two options.
Those are two separate choices and discussions.
Aristotle Pagaltzis // <http://plasmasturm.org/>
More information about the Markdown-Discuss