71 <dd><p><a rel="help" href="http://www.w3.org/TR/html401/struct/links.html#adef-rel">HTML4 definition of the 'rel' attribute.</a> Here are some additional values, each of which can be used or omitted in any combination (unless otherwise noted, and except where prohibited by law) and their meanings, <dfn title="A symmetric relationship 'rel' is one where 'A rel B' implies 'B rel A' and vice versa.">symmetry</dfn>, <dfn title="A transitive relationship 'rel' is one where 'A rel B' and 'B rel C' implies 'A rel C'">transitivity</dfn> and <dfn title="A relationship 'rel' has an inverse 'inv' when 'A rel B' implies 'B inv A'. A symmetrical relationship is its own inverse.">inverse</dfn> if any. Please see the <a href=".">XFN home page</a> for more information about <abbr title="XHTML Friends Network">XFN</abbr>.</p>
72
73 <div><h3>friendship (pick at most one)</h3>
74
75 <dl>
76
77 <dt id="contact">contact</dt>
78
79 <dd>Someone you know how to get in touch with. Often symmetric.</dd>
80
81 <dt id="acquaintance">acquaintance</dt>
82
83 <dd>Someone who you have exchanged greetings and not much (if any) more — maybe a short conversation or two. Often symmetric.</dd>
84
85 <dt id="friend">friend</dt>
86
87 <dd>Someone you are a friend to. A compatriot, buddy, home(boy|girl) that you know. Often symmetric.</dd>
88
89 </dl>
90
91 </div>
92
93 <div><h3>physical</h3>
94
95 <dl>
96
97 <dt id="met">met</dt>
98
99 <dd>Someone who you have actually met in person. Symmetric.</dd>
100
101 </dl>
102
103 </div>
104
105 <div><h3>professional</h3>
106
107 <dl>
108
109 <dt id="co-worker">co-worker</dt>
110
111 <dd>Someone a person works with, or works at the same organization as. Symmetric. Usually transitive.</dd>
112
113 <dt id="colleague">colleague</dt>
114
115 <dd>Someone in the same field of study/activity. Symmetric. Often transitive.</dd>
116
117 </dl>
118
119 </div>
120
121 <div><h3>geographical (pick at most one)</h3>
122
123 <dl>
124
125 <dt id="co-resident">co-resident</dt>
126
127 <dd>Someone you share a street address with. Symmetric and transitive.</dd>
128
129 <dt id="neighbor">neighbor</dt>
130
131 <dd>Someone who lives nearby, perhaps only at an adjacent street address or doorway. Symmetric. Often transitive.</dd>
132
133 </dl>
134
135 </div>
136
137 <div><h3>family (pick at most one)</h3>
138
139 <dl>
140
141 <dt id="child">child</dt>
142
143 <dd>A person's genetic offspring, or someone that a person has adopted and takes care of. Inverse is parent.</dd>
144
145 <dt id="parent">parent</dt>
146
147 <dd>Inverse of child.</dd>
148
149 <dt id="sibling">sibling</dt>
150
151 <dd>Someone a person shares a parent with. Symmetric. Usually transitive.</dd>
152
153 <dt id="spouse">spouse</dt>
154
155 <dd>Someone you are married to. Symmetric. Not transitive.</dd>
156
157 <dt id="kin">kin</dt>
158
159 <dd>A relative, someone you consider part of your extended family. Symmetric and typically transitive.</dd>
160
161 </dl>
162
163 </div>
164
165 <div><h3>romantic</h3>
166
167 <dl>
168
169 <dt id="muse">muse</dt>
170
171 <dd>Someone who brings you inspiration. No inverse.</dd>
172
173 <dt id="crush">crush</dt>
174
175 <dd>Someone you have a crush on. No inverse.</dd>
176
177 <dt id="date">date</dt>
178
179 <dd>Someone you are dating. Symmetric. Not transitive.</dd>
180
181 <dt id="sweetheart">sweetheart</dt>
182
183 <dd>Someone with whom you are intimate and at least somewhat committed, typically exclusively. Symmetric. Not transitive.</dd>
184
185 </dl>
186
187 </div>
188
189 <div><h3>identity</h3>
190
191 <dl>
192
193 <dt id="me">me</dt>
194
195 <dd>A link to yourself at a different URL. Exclusive of all other XFN values. Required symmetric. There is an implicit "me" relation from the contents of a directory to the directory itself.</dd>
196
197 </dl>
198
199 </div>
200
201 </dd>
202
203 </dl>
204
205 <h2>Acknowledgments</h2>
206
207 <p>Please see our <a href="thanks">Thanks page</a> for acknowledgments.