Subject: registration request for dns-prefetch, preconnect, prefetch, and prerender link relation types

From: Erik Wilde <[email-masked]>
Date: Mon, 25 Jan 2016 16:54:37 -0800

hello link-relations.

https://www.w3.org/TR/2016/WD-resource-hints-20160126/#iana-considerations 
defines 4 new link relation types that should be added to the IANA link 
relation registry. here is an excerpt with the link relation type 
descriptions:

-------------------------------------

7.1 dns-prefetch Link Relation Type

Relation Name: dns-prefetch
Description: The dns-prefetch link relation type is used to indicate an 
origin that will be used to fetch required resources, and that the user 
agent SHOULD resolve as early as possible.

7.2 preconnect Link Relation Type

Relation Name: preconnect
Description: The preconnect link relation type is used to indicate an 
origin that will be used to fetch required resources. Initiating an 
early connection, which includes the DNS lookup, TCP handshake, and 
optional TLS negotiation, allows the user agent to mask the high latency 
costs of establishing a connection.

7.3 prefetch Link Relation Type

Relation Name: prefetch
Description: The prefetch link relation type is used to declare a 
resource that might be required by the next navigation, and that the 
user agent SHOULD fetch, such that the user agent can deliver a faster 
response once the resource is requested in the future.

7.4 prerender Link Relation Type

Relation Name: prerender
Description: The prerender link relation type is used to declare an HTML 
resource that might be required by the next navigation, and that the 
user agent SHOULD fetch and execute, such that the user agent can 
deliver faster response and processing once the resource is requested in 
the future.

-------------------------------------

if there are any concerns or questions about these link relations types, 
please let us know.

thanks a lot and cheers,

dret.

-- 
erik wilde | mailto:[email-masked] |
            | http://dret.net/netdret    |
            | http://twitter.com/dret    |

---

From: Julian Reschke <[email-masked]>
Date: Tue, 26 Jan 2016 07:13:03 +0100

My gut reaction is: why do we need a whopping 5 link relations 
(including preload)?

7.1 and 7.2 look very similar; they also need to talk about the link 
context's origin so that people are not tempted to insert just the origin.

7.3 and 7.4 look very similar as well; 7.4 also needs to be rephrased to 
be independent of the media type.

Best regards, Julian

---

From: Mark Nottingham <[email-masked]>
Date: Sun, 31 Jan 2016 13:10:56 +1100

My .02 -

5988 doesn't require strong justification for registering a relation type; only that it follows certain rules. So, I'd say the fact that these relations went through an open process is enough to overcome any reluctance to register so many.

Talking about the context of the link is nice; see existing registry entries for examples.

WRT 7.4 - the applicable text in 5988 is:

"""
Registered relation types MUST NOT constrain the media type of the
   context IRI, and MUST NOT constrain the available representation
   media types of the target IRI.  However, they can specify the
   behaviours and properties of the target resource (e.g., allowable
   HTTP methods, request and response media types that must be
   supported).
"""

Putting RFC1918 language in registry entries is a bit weird too.

So something like this would be clearer:

"""
Indicates a resource that might be required by the next navigation, and that user agents ought to fetch and execute to improve performance.
"""

Cheers,

> On 26 Jan 2016, at 5:13 pm, Julian Reschke <[email-masked]> wrote:
> 
> My gut reaction is: why do we need a whopping 5 link relations (including preload)?
> 
> 7.1 and 7.2 look very similar; they also need to talk about the link context's origin so that people are not tempted to insert just the origin.
> 
> 7.3 and 7.4 look very similar as well; 7.4 also needs to be rephrased to be independent of the media type.
> 
> Best regards, Julian
> 
> 
> _______________________________________________
> link-relations mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/link-relations

--
Mark Nottingham   https://www.mnot.net/

---

From: Erik Wilde <[email-masked]>
Date: Sat, 30 Jan 2016 20:56:47 -0800

> 5988 doesn't require strong justification for registering a relation type; only that it follows certain rules. So, I'd say the fact that these relations went through an open process is enough to ov…

that was my gut reaction. seeing 4 or 5 link relations as a "whopping 
amount" seems a bit overstated (after all, the namespace is fairly big, 
so there's no need to be overly conservative trying to conserve space), 
but i guess you mileage may vary.

> Indicates a resource that might be required by the next navigation, and that user agents ought to fetch and execute to improve performance.

i like it. personally. i think that it's a very good idea to not 
constrain link relations any more than they have to be, and as mark 
point out, when it comes to media types, it's not even something you're 
supposed to do.

https://github.com/w3c/resource-hints/pull/54 adopts mark's suggested 
change, and afaict, this does not lose anything in terms of what the 
spec is saying.

thanks and cheers,

dret.