+|_. Attribute|_. Type|_. Description|_. Example|
+|object_uuid|string|The arvados object that is the subject of the log.||
+|event_at|datetime|||
+|event_type|string|A user-defined category or type for this event.|@LOGIN@|
+|summary|text|||
+|properties|hash|||
+
+h3. Creation
+
+Any user may create Log entries for any event they find useful. User-generated Logs have no intrinsic meaning to other users or to the Arvados system itself; it is up to each user to choose appropriate log event types and summaries for their project.
+
+h3. System Logs
+
+Arvados uses Logs to record creation, deletion, and updates of other Arvados resources.