+|_. Attribute|_. Type|_. Description|
+|head_uuid|string|The object being described or acted on.|
+|tail_uuid|string|The origin or actor in the description or action (may be null).|
+|link_class|string|Type of link|
+|name|string|Primary value of the link.|
+|properties|hash|Additional information, expressed as a key→value hash. Key: string. Value: string, number, array, or hash.|