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From: Nathaniel Borenstein <nsb@guppylake.com>
In-Reply-To: <4EBB7660.6040904@dcrocker.net>
Date: Thu, 10 Nov 2011 09:02:27 -0500
Message-Id: <678FC35A-1730-48BE-A0F2-152E5D49BC10@guppylake.com>
References: <4EBB3CFC.5050608@dcrocker.net> <4EBB5310.6080103@it.aoyama.ac.jp>
 <CAC4RtVBNL_nTCwBsMQpEKS9kXUF7aj9yEstef7yrzwi8qYAQDg@mail.gmail.com>
 <4EBB7660.6040904@dcrocker.net>
To: dcrocker@bbiw.net
Cc: Apps Discuss <apps-discuss@ietf.org>
Subject: Re: [apps-discuss] seeking pragmatic guidelines for content-type
 'structure': when to go top-level?
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One other pragmatic condition might indicate the desirability of a =
top-level type:  the possibility of defining a reasonable default =
behavior for unrecognized subtypes.

Thus, for text/*, it is sometimes reasonable to just show users the raw =
text.  For image/* with an unrecognized subtype, it is sometimes =
reasonable to invoke a "smarter" program like xv.  For multipart/* you =
can at least find the parts, even if you're not sure what to do with =
them.  For video/* you  might choose to reject or strip out the data in =
a resource-challenged environment.  And I suspect this argues in favor =
of "font" as a TLCT, as the mail code may often be able to pass the data =
on to a "smarter" font engine.

I believe this is related, but not identical, to #1 and #2 below.  -- =
Nathaniel


On Nov 10, 2011, at 1:59 AM, Dave CROCKER wrote:

>     So, I think this leaves guidance in favor of a new top-level =
content-type if one or more of the following apply:
>=20
>     1.  Strong semantic relationship among the sub-types
>=20
>     2.  Likelihood of some common code for the set of sub-types
>=20
>     3.  Expectation that implementors will benefit from easily =
discovering the current set of sub-types in the registry.
>=20
>=20
> Does this summarize the guidance that should be offered for justifying =
a new TLCT?


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<html><head></head><body style=3D"word-wrap: break-word; =
-webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">One =
other pragmatic condition might indicate the desirability of a top-level =
type: &nbsp;the possibility of defining a reasonable default behavior =
for unrecognized subtypes.<div><br></div><div>Thus, for text/*, it is =
sometimes reasonable to just show users the raw text. &nbsp;For image/* =
with an unrecognized subtype, it is sometimes reasonable to invoke a =
"smarter" program like xv. &nbsp;For multipart/* you can at least find =
the parts, even if you're not sure what to do with them. &nbsp;For =
video/* you &nbsp;might choose to reject or strip out the data in a =
resource-challenged environment. &nbsp;And I suspect this argues in =
favor of "font" as a TLCT, as the mail code may often be able to pass =
the data on to a "smarter" font engine.</div><div><br></div><div>I =
believe this is related, but not identical, to #1 and #2 below. &nbsp;-- =
Nathaniel</div><div><br></div><div><br><div><div>On Nov 10, 2011, at =
1:59 AM, Dave CROCKER wrote:</div><br =
class=3D"Apple-interchange-newline"><blockquote type=3D"cite"><span =
class=3D"Apple-style-span" style=3D"border-collapse: separate; =
font-family: Helvetica; font-style: normal; font-variant: normal; =
font-weight: normal; letter-spacing: normal; line-height: normal; =
orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: =
none; white-space: normal; widows: 2; word-spacing: 0px; =
-webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: =
0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: =
auto; -webkit-text-stroke-width: 0px; font-size: medium; =
">&nbsp;&nbsp;&nbsp;&nbsp;So, I think this leaves guidance in favor of a =
new top-level content-type if one or more of the following =
apply:<br><br>&nbsp;&nbsp;&nbsp;&nbsp;1. &nbsp;Strong semantic =
relationship among the sub-types<br><br>&nbsp;&nbsp;&nbsp;&nbsp;2. =
&nbsp;Likelihood of some common code for the set of =
sub-types<br><br>&nbsp;&nbsp;&nbsp;&nbsp;3. &nbsp;Expectation that =
implementors will benefit from easily discovering the current set of =
sub-types in the registry.<br><br><br>Does this summarize the guidance =
that should be offered for justifying a new =
TLCT?<br></span></blockquote></div><br></div></body></html>=

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