child

Hypertext links in HTML (draft)

      CHILD
         The CHILD relationship identifies a subordinate or
         subdocument. Any document may have multiple CHILD documents
         within the same hierarchy.

         When REL=CHILD, the target document is a hierarchical child,
         or subdocument, of the current document.

         When REV=CHILD, the current document is the hierarchical
         child, or subdocument, of the target.

[引用： 4.4d. Hierarchy Links -- Hypertext links in HTML (draft) より]