Network Working Group J. Snell
Internet-Draft
Intended status: Informational October 22, 2013
Expires: April 25, 2014
Additional Link Relations and the urn:social Namespace
draft-snell-more-link-relations-02
Abstract
This specification defines a number of additional Link Relation Types
that can used for a variety of purposes.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. The 'social' URN Namespace . . . . . . . . . . . . . . . . . 2
2.1. urn:social:everyone . . . . . . . . . . . . . . . . . . . 4
2.2. urn:social:direct . . . . . . . . . . . . . . . . . . . . 4
2.3. urn:social:extended . . . . . . . . . . . . . . . . . . . 4
2.4. urn:social:peer . . . . . . . . . . . . . . . . . . . . . 4
2.5. urn:social:subordinate . . . . . . . . . . . . . . . . . 4
2.6. urn:social:superior . . . . . . . . . . . . . . . . . . . 5
2.7. urn:social:common . . . . . . . . . . . . . . . . . . . . 5
2.8. urn:social:interested . . . . . . . . . . . . . . . . . . 5
2.9. urn:social:self . . . . . . . . . . . . . . . . . . . . . 5
2.10. urn:social:role:{tokens} . . . . . . . . . . . . . . . . 5
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
3.1. Relationship of 'to', 'bto', 'cc', 'bcc', 'from', 'bfrom'
and 'scope' . . . . . . . . . . . . . . . . . . . . . . . 7
4. Security Considerations . . . . . . . . . . . . . . . . . . . 7
5. Informative References . . . . . . . . . . . . . . . . . . . 7
Appendix A. Examples . . . . . . . . . . . . . . . . . . . . . . 7
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
This specification defines and adds the following additional link
relation types to the IANA Registry of Link Relations established by
[RFC5988]: to, bto, cc, bcc, from, bfrom, source, generator,
provider, location, alias and mentioned-by. Further, this
specification proposes a new 'social' URN namespace.
Note that this document is a work-in-progress draft specification
that does not yet represent a "standard". It is the intention of
this specification to propose a few new ideas and openly solicit
feedback on their definition and use. While this document might
eventually evolve into an RFC the ideas described herein have not yet
been broadly implemented and have definitions that may evolve through
successive iterations of this draft.
2. The 'social' URN Namespace
This specification defines the 'social' URN namespace having the
following structure:
ABNF Grammar:
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social-url = "urn:social:" social-nss
NZDIGIT = %x31-39
distance = ":" NZDIGIT
confidence = ":" 2DIGIT
social-nss = "self" /
"everyone" /
"direct" /
( "extended" [ distance ] ) /
( "peer" [ distance ] ) /
( "subordinate" [ distance ] ) /
( "superior" [ distance ] ) /
( "common" [ confidence ] ) /
( "interested" [ confidence ] ) /
( "role" ":" TOKEN )
Within any given social networking system, there is an available
population of entities. Each NSS term represent specific subsets of
this population and are defined in terms of these subsets relative to
a fixed context. For example, if the fixed content is a person, the
"urn:social:direct" URN identifies the subset of the total population
that is directly connected to the context person within the social
graph, while the "urn:social:extended" URN identifies the subset that
is directly or indirectly connected to the context person.
The "extended", "peer", "subordinate", and "superior" NSS values MAY
include an additional single digit non-zero "distance" specifier,
whose value identifies a "degree of separation" from the link
context. For instance, the URN "urn:social:extended:1" would
identify members of the context's extended network that are only 1
degree of separation from the context (which is equivalent to the
"urn:social:direct" URN). The value "urn:social:extended:6"
indicates six degrees of separation from the context. If the
distance is omitted from the NSS, no limit to the distance is
assumed.
The "common" and "interested" NSS values MAY include a two-digit
"confidence factor" whose value specifies a confidence interval an
implementation can apply when determining which members of the total
population ought to be considered. The values range from 00-99,
corresponding to confidence intervals between 0% to 99%. If the
confidence factor is omitted from the NSS, a confidence interval of
100% is assumed.
The "role" NSS value MUST include one or more semicolon ";" TOKEN
delimited segments whose values identify specific named "roles"
within the population. For instance, the URN
"urn:social:role:editor" identifies all members of the relevant
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population who are assigned to the "editor" rolel. The URN
"urn:social:role:reader;writer" identifes all members of the relevant
population who are assigned to both the "reader" and "writer" roles.
The 'social' URN namespace is defined to be intentionally ambiguous
and highly dependent on context. The specific interpretation of each
NSS, including any distance or confidence specifiers, depend entirely
on how and where the NSS is being used.
2.1. urn:social:everyone
The "urn:social:everyone" URN identifies the subset of the total
population that is visible to the context.
2.2. urn:social:direct
The "urn:social:direct" URN identifies the subset of the total
population that is both visible to and directly connected to the
context.
2.3. urn:social:extended
The "urn:social:extended" URN identifies the subset of the total
population that is visible to and connected either directly or
indirectly to the context.
2.4. urn:social:peer
The "urn:social:peer" URN identifies the subset of the total
population that is both visible to the context and considered to be a
"peer".
Peer relationships exist only within populations in which there
exists a hierarchical division of members in the population. An
example of such a network would be a company or similarly structured
organization. Peers might be directly or indirectly connected to the
target resource but are considered to share the same hierarchical
position.
2.5. urn:social:subordinate
The "urn:social:subordinate" URN identifies the subset of the total
population that is both visible to the context and considered to be
"subordinate" to the context.
Subordinate relationships exist only within populations in which
there exists a hierarchical division of members in the population.
An example of such a network would be a company or similarly
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structured organization. Subordinates might be directly or
indirectly connected to the target resource but are considered to
share a lower hierarchical position.
2.6. urn:social:superior
The "urn:social:superior" URN identifies the subset of the total
population that is both visible to the context and considered to be
"superior" to the context.
Superior relationships exist only within populations in which there
exists a hierarchical division of members in the population. An
example of such a network would be a company or similarly structured
organization. Superiors might be directly or indirectly connected to
the target resource but are considered to have a higher hierarchical
position.
2.7. urn:social:common
The "urn:social:common" URN identifies the subset of the total
population that is both visible to the context and is determined to
share common attributes with the context.
Determination of "common attributes" is dependent entirely on the
application. For example, an application might choose to use shared
interests in a given topic as the "common attribute" binding a
particular grouping of members.
2.8. urn:social:interested
The "urn:social:interested" URN identifies the subset of the total
population that is both visible to the context and has an express
interest in the context. Examples of members of the "interested"
subset are those who have elected to "follow" the activity of the
context resource.
2.9. urn:social:self
The "urn:social:self" URN identifies the context resource itself as a
member of the total population.
2.10. urn:social:role:{tokens}
The "urn:social:role:{token}" URN identifies the subset of the total
population that is both visible to the contexst and has been assigned
to each of the individual roles identified within by the URN.
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The values of the role tokens are specific to the context in which
they are being used.
3. IANA Considerations
The following Link Relations are added to the IANA Registry of Link
Relations.
+-----------------+-------------------------------------------------+
| Name | Description |
+-----------------+-------------------------------------------------+
| to | Refers to a resource that is considered to be |
| | part of the public primary audience of the |
| | link's context. |
| bto | Refers to a resource that is considered to be |
| | part of the private primary audience of the |
| | link's context. |
| cc | Refers to a resource that is considered to be |
| | part of the public secondary audience of the |
| | link's context. |
| bcc | Refers to a resource that is considered to be |
| | part of the private secondary audience of the |
| | link's context. |
| from | Refers to a resource that is publicly |
| | considered to be the originator of the link's |
| | context. |
| bfrom | Refers to a resource that is privately |
| | considered to be the orignator of the link's |
| | context. |
| scope | Refers to a resource that identifies the total |
| | population of entities to which the context is |
| | relevant. |
| source | Refers to the original source of information |
| | contained by the context resource. |
| provider | Refers to the resource that provided the |
| | context resource. Typically, this would be |
| | used to identify the entity publishing the |
| | resource. |
| generator | Refers to the resource that generated the |
| | context resource. Typically, this would be |
| | used to identify the software application that |
| | created the context resource. |
| mentioned-by | Refers to a resource that mentions the context |
| | resource in some fashion. This, for example, |
| | would be used when an article mentions another |
| | article, or a social status update mentions a |
| | particular user, etc. |
| location | References a URI/IRI that represents a physical |
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| | or logical location with which the context |
| | resource is associated. |
+-----------------+-------------------------------------------------+
3.1. Relationship of 'to', 'bto', 'cc', 'bcc', 'from', 'bfrom' and
'scope'
The "scope" link relation is closely aligned with the so-called
"audience targeting" link relations "to", "bto", "cc", "bcc", "from",
and "bfrom" in that "scope" links identify the total population from
which the audience is drawn.
4. Security Considerations
There are no additional security concerns introduced by this
document.
5. Informative References
[RFC5988] Nottingham, M., "Web Linking", RFC 5988, October 2010.
Appendix A. Examples
Using targeting link relations and the urn:social namespace:
POST /alerts HTTP/1.1
Host: example.org
Content-Type: text/plain
Authorization: Basic {Base64 Credentials}
Link: <urn:social:everyone>; rel="to"
Link: <urn:social:extended:2>; rel="cc"
Link: <urn:social:self>; rel="bfrom"
Link: <http://example.net/my-social-net>; rel="scope"
Test message
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Using the targeting link relations with urn:social:role:
POST /alerts HTTP/1.1
Host: example.org
Content-Type: text/plain
Authorization: Basic {Base64 Credentials}
Link: <urn:social:role:moderator>; rel="to"
Link: <urn:social:role:editor>; rel="cc"
Test message
Using publication link relations:
<html>
<head>
...
<link
rel="source"
href="http://example.net/post/1" />
<link
rel="provider"
href="http://example.org" />
<link
rel="generator"
href="http://example.com/software/app/1.1" />
...
</head>
<body>...</body>
</html>
Using the location relation:
Link: <geo:37.786971,-122.399677>; rel="location"
Using the mentioned-by relation:
LINK /articles/1 HTTP/1.1
Host: example.org
Link: <articles/2>; rel="mentioned-by"
Author's Address
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James M Snell
Email: jasnell@gmail.com
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