决窍....确保网络的每个有限的机械部份、每个应用程序本身由简单的不会很强大的部分组成

Tim Berners-Lee, 编织网络

"尽可能的简单"是我们把XFN规范放在一起的操作运行哲理。简单不是容易，在你第一次看到集成XFN的一小套值时，已经溶入了很多的思想。对每种事情都会有个理由，而在这个文档里，我们就是真对我们只谈为什么我们选择这样事情的理由。

也许最强大的驱动XFN诞生的力量是简单。 重点而于允许各种关系描述下XFN简介里的一套值是尽可能的小和简单。在有些情况下，意味着如果某些值的应用有问题，则从简介中拿掉。而这样会减少能用XFN描述的关系的范围，作者可以从一小套值开始并在以后添加，比定义大量的值而有些很少或跟本用不上要强。XFN是简单的角色将不会变得很强大

另一个驱动的XFN设计原则是分散性, 就象网络本身。用给作者放置XFN的权力，建制XFN数据的工作并保持当前信息是分布式的。这意味着作者对他们的XFN信息有控制权，而集中式模型则不是这样。

XFN值的第三个设计原则是描述两个人之间的自然关系，而不是人们本身。我们觉得一个人的站点（如网志）内容会说介绍很多他们的事情而无需抓取任何一套值。不管怎样，人们之间的关系更容易刻画。自从网络提供了一个机械的链接从（就是说从一个地方跳到另一个地方），很多这些节点是从一个人的站点跳到另一个人的站点，这让人觉得可以利用这些已存在链接。XFN设想以XFN增强链接点的在线节点代表了一个人。对网志来说几乎总是这样，但也许是整个网络站点的事实。

为什么我们选择把这些值放到XHTML里而不是新建一套基于XML的语法呢？ 第一件事，创建基于XML语法已经完成，在我们看来，没有理同重蹈其它人的复辙。更重要的是我们愿创建在一个已存在的网络架构上面。就象Tim Berners-Lee写道：“网络来自于一些想法，这些想法能单独的与现存的或将来的部分溶合。"^{[ href="http://gmpg.org/xfn/background#fn1" name=b1>1]} 在XFN后面的想法就是添加一个新的概念能够更容易的交互于已存在（大量的）的网络单元。我们选择使用XHTML属性rel, 已经存在并被定义用来描述关系。相对于文档关系来说，我们简单的扩展成描述人类关系。 由于其基于XHTML，XFN就很容易随手创建，并且机器和人都可以阅读。由于建于XHTML上，我们无需再创建一整套崭新的语言来增强已经存在的链接。

Friendship友谊

把广泛和微妙的人类关系总结成两个值看起来很放肆。但简单的目标让我们做这样的选择。不想尝试覆盖各种可能的值，我们决定采用大家所熟知的两种共同层次：

Friend朋友是一个在很多时候很难描述的值。亚里斯多德说过：“想成为朋友是很快的，但友谊是慢慢成熟的果子。”因为果实会在不同的时间成熟，所以熟人和朋友之间的分隔线由人而异。Joe也许经过一次交谈后就把某人归我朋友。而Brace会觉得朋友的类别要用在经常沟通并有很深信任的人上。

Acquaintance熟人 implies a mutual familiarity and an
individual's definition is not likely to vary significantly from person to
person, therefore it suggests symmetry but doesn't possess it by definition.
(For something lighter, try met.) friend should be
stronger in implied symmetry. Because of aforementioned variances, it is more
likely that there will be disparities (or mis-matches) with the
friend朋友 value than most others. You should not be offended if
someone doesn't reciprocate a friend value, because even though you
may feel the same about your relationship with each other, you may just have
different ideas of what a friendship entails. Or they may just have forgotten.

While more values may be introduced in the future, the authors feel that
these values are sufficient for the initial version of XFN. The problem with
values such as "close-friend," which we considered, is that they open the door
to a great many variations on the same theme, which runs counter to the wish to
keep XFN simple.

Physical亲身接触的

Met认识 is most likely the value easiest to claim. It is very
straight-forward; either you have met someone in person (or title="In Real Life">IRL as we sometimes say) or you haven't.
met can indeed exist independently of every other value, including,
though not likely, spouse. This value (and indeed the genesis of
XFN) was inspired by a comment made by href="http://www.lifestudent.com/">John Halcyon Styn during the SxSW 2003
session "Beyond the Blog."

Although the possibility of other physical relationship terms led to a great
deal of humor among the authors, met seems sufficient for the
initial release.

Professional专业的

After the familial, romantic, and friendship relationship types were created,
it became apparent that some values were needed to describe relationships that
may exist outside of the personal sphere. One of the most common environments in
which relationships form is work. These relationships may include a friendship
component, or may not.

Co-worker同事 describes a person who shares an employer with
you. This could be a member of your office team, your division, or simply works
for the same company. It can also describe your manager, your subordinates, the
CEO, and anyone else at your workplace. Note also that this value is not
geographically limited, so a co-worker can be someone who is located in a
different city or country.

Colleague校友 refer to a person who you regard as a peer; that
is, someone who you feel is on your level and has skills and interests similar
to your own. A colleague does not have to be a co-worker, although of course can
be. For example: two doctors and a lawyer are members of a quilting circle.
While they all share an interest in quilting, only the two doctors are
colleagues, whereas the lawyer is colleague to neither of them (and vice versa).

Some other obvious choices for this section would have been "supervisor" and
"subordinate." These seemed too detailed to fit in with the drive for
simplicity, and are effectively covered by the value co-worker.
Representation of such work relationships may appear in a future version of XFN.

Geographical地埋上的

There are much more exact methods of describing your location (and your
location relative to others) using methods such as href="http://geourl.org/">GeoURL, and we do not seek to replace them. The
geographical values of XFN are descriptive of the relationship itself. For this
reason there are only two possible values, co-resident and neighbor, which are
mutually exclusive.

Co-resident同地方人 is pretty specific insofar that it dictates that
you share a street address with the person you're referring to. This is broad
enough to allow for co-residents with the same apartment building and such, yet
still specific enough to suggest the relationship is effected by the close
proximity. Co-resident is symmetric.

Neighbor邻居 is much broader, and deliberately so. Different
people may have different definitions of what "neighbor" might mean to them, and
they are all valid. Some might consider neighbor in the very strict sense of
being someone you live next door to, others might take a more Mr. Rogers
approach to the concept of neighbor and extend it further, though to fit with
XFN it should still have definite geographical connotations. Due to possible
various personal interpretations of this value, it is not necessarily symmetric,
though it certainly may be.

There was some discussion of values such as "countryman" or a way to
represent that another person lives in the same city. These were ultimately left
out because they did not seem to represent useful information.

Family家庭

The most common relationship types are, of course, familial. A great deal of
discussion centered on the degree to which family relationships should be
described. In the end, the goal of simplicity won out over the desire to create
a detailed list. Thus XFN contains three family-relationship values.

Child孩子 means that the person to who you are linking is
someone you parented. Note that this does not require that you actually be the
biological parent of the child; adoptive children also qualify.

Parent父母 is the inverse of child, and refers to a
person who parented you, whether biological or adoptive.

Sibling兄弟姐妹 refers to a person with whom you share a parent.
Brothers, sisters, half-brothers, and half-sisters are all examples of siblings.

Spouse配偶 refers to a person to whom you feel yourself to be
married, whether legally or not. The use of spouse should be
symmetric. A spouse could also be considered a romantic value,
however, we concluded that a major difference between spouse and the other
romantic values is that a spouse is considered to be part of a family, whereas
this is not typically true for the other romantic values. Also, though typically
a 1:1 relationship, some localities, cultures (and subcultures) permit and
encourage one to many spousal relationships. We leave such complexities up to
individual choice and judgment.

Obviously a great many more values could have been included, but we
discovered some interesting barriers. For example, "aunt" and "uncle" are
gender-specific, and we could find no gender-neutral words for "sibling of a
parent" in the English language. Without those terms, including the
gender-neutral "cousin" made little or no sense. We considered adding
"grandparent," but in the end dropped the term because it seemed unlikely to be
used in the near future. It may appear in future versions of XFN.

Romantic浪漫的

It can be argued that the most interesting relationships are those involving
romance, and XFN could not be complete without romantic descriptors. Indeed,
this section has the most values of any part of XFN, and caused the most debate
among the authors.

Muse女神 describes a person who inspires you in some way. This
may not be a strictly romantic or erotic type of inspiration, but might also be
used to describe a person who has provided you with professional inspiration.
The value landed in the romantic section because inspiration is a romantic
concept in the general sense (rather than a rational concept).

Crush迷恋 refers to a person to whom you are attracted, perhaps
even strongly, but who might not express the same feeling in return, or even
know that you exist. Crushes are also usually secret, which makes their
inclusion in XFN (a public data set) somewhat interesting. We expect that the
use of crush in XFN will be in a teasing manner, as between two
friends who like to flirt but do not actually date.

Date约会 is used to refer to a person you are dating; that is,
whom you see on a regular basis. This usually means that you specially arrange
times and places to see the other person, such as going out to dinner and a
movie, or going to see the orchestra together. What distinguishes this from
ordinary friendship is that there is a romantic component involved. We do not
take a position on exclusivity here: a single person can mark any number of
others as being a date. Whether or not they should is up to the
people involved.

Sweetheart甜心 describes a person with whom you are intimate,
whether physically or emotionally, and to whom you are committed to some degree.
As with date, there is no requirement that sweetheart
apply to a single person, although it is typical that a person will have only
one romantic sweetheart at a time. This value was the best gender-neutral term
we could find to represent the more common terms "girlfriend" and "boyfriend,"
which it is meant to represent, as well as informal terms like "snookums",
"honey", "pumpkin", and "sweetie-pie".

There were a whole pile of love, romance, and sexually oriented terms we
considered and discarded. Some were rejected on the grounds they were
unnecessary or example, polyamorous individuals can indicate their other
partners using values already defined (having two links marked
sweetheart or spouse, for example). Others were left
out because they did not fit with the desire to keep XFN simple. The current set
seems to us to accurately capture a sufficiently detailed range of romantic
feelings without becoming overwhelming.

A special note is merited for the omission of a term to describe a person to
whom one is engaged. The terms "fianc? and "fiance? are gender-specific, which
was a problem. We also decided that describing engagement should be left out
since it is intended as a transitional state of affairs, as a prelude to
marriage (and thus the value spouse, which is a less intentionally
temporary relationship).

Deliberate limitations局限性讨论

As explained in many categories above, many choices of relationship terms
were omitted, typically for simplicity. There are a few general reasons why
certain values and even sets of values were left out.

Gender neutrality 性别中立(and avoiding other personal attributes)

Values like brother and sister were omitted for the
gender-neutral sibling deliberately to keep gender-implying
information out of XFN. The reasons are important, if a bit subtle.

When you annotate a hyperlink to someone with rel='friend' for
example, you are saying that you are a friend to that person. Whether or not
you consider yourself to be a friend of someone else is something under
your control, something which you yourself are the authority over, and thus it
makes sense that you be able to specify it. In addition, you are describing
precisely the relationship between you two from your
perspective, and nothing more. You are not describing anything about
the other person, such as their race, age, preferences, or gender for that
matter. While some or most of these attributes may be persistent, and
thus you may be able to condfidently say what they are, the problem with saying
so is that you are not the authority over another person's attributes.
Only the person themselves can authoritatively describe such attributes about
themselves. And certainly it does not make any sense to mix such attributes with
your description of your relationship with them.

Perhaps someone else will invent a markup language or some other mechanism to
describe attributes about a person, and then people could use that to
describe themselves. That's not the purpose of XFN and outside it's focus, so we
leave that problem to other solutions.

Positive or neutral relationships only正的或仅中立关系

Negative relationship terms have been omitted from XFN by design. The authors
think that such values would not serve a positive ends and thus made the
deliberate decision to leave them out. Such terms (we won't even bother naming
them here) while mildly entertaining in a dark humor sort of way, only serve to
propagate negativity.

The authors do not deny that such negative relationships exist in the real
world today. Of course they exist. However, we see no need nor benefit to
standardizing such relationships and capturing them in a form which would spread
on the Web. There is enough hatred in the world. We should work to eliminate
hatred, not to spread it.

And we do realize that by creating XFN and
the mechanisms it uses (XMDP), we have opened
a Pandora's box, and have made it easier for those that would create and
propagate negative relationships. We can only hope that our positive creation
wins out over any such negative creations.

Out of time过时

With XFN itself there is no way to indicate that you used to be friends with
someone, or that someone is your ex-crush etc. XFN values are by implication
present tense.

We have chosen to omit any temporal component for the sake of simplicity.

That being said, it is possible to mix XFN with a time based format
to capture the temporal (and even ephemeral) nature of many relationships. Blogs
by their very nature are a time based format. It is possible to use XFN values
to refer to people linked to within a blog post. It could then be presumed that
those relationships were as defined as of the timestamp of that blog post. Later
blog posts could mention the same people with different XFN values. By viewing a
set or series of blog posts and watching the XFN values on the interpersonal
links change, one could easily derive implied temporal information about the
nature of the relationships. Note that the lack of a rel attribute
on an interpersonal link should not be taken to mean anything in terms of the
nature or change(s) thereof a relationship.

Exception. Clearly the value met has temporal implications, and
yet, is such a useful value that we made an exception and included it anyway. To
that extent, met can be considered a description of your
relationship with someone which is still presently true, in that you
have physically met, and that you always will have physically met. The same
could be said about other physical relationships, e.g. shook-hands, hugged,
kissed etc. and thus the door is left slightly open to such possibilities for
future versions of XFN.