[1] XForms 1.1 (10/20/2009, 1:51:54 PM 版) <http://www.w3.org/TR/2009/REC-xforms-20091020/#fn-if>
[2] draft-ietf-core-link-format-14 - CoRE Link Format ( (6/4/2012, 9:03:10 PM 版)) <http://tools.ietf.org/html/draft-ietf-core-link-format-14#section-3.2>
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