|@is_a@|string|Arvados object type|@["head_uuid","is_a","arvados#collection"]@|
|@exists@|string|Test if a subproperty is present.|@["properties","exists","my_subproperty"]@|
-h4. Filtering on subproperties
+h4(#subpropertyfilters). Filtering on subproperties
Some record type have an additional @properties@ attribute that allows recording and filtering on additional key-value pairs. To filter on a subproperty, the value in the @attribute@ position has the form @properties.user_property@. You may also use JSON-LD / RDF style URIs for property keys by enclosing them in @<...>@ for example @properties.<http://example.com/user_property>@. Alternately you may also provide a JSON-LD "@context" field, however at this time JSON-LD contexts are not interpreted by Arvados.
|_. Attribute|_. Type|_. Description|_. Example|
|name|string|||
|description|text|||
+|properties|hash|User-defined metadata, may be used in queries using "subproperty filters":{{site.baseurl}}/api/methods.html#subpropertyfilters ||
|portable_data_hash|string|The MD5 sum of the manifest text stripped of block hints other than the size hint.||
|manifest_text|text|||
|replication_desired|number|Minimum storage replication level desired for each data block referenced by this collection. A value of @null@ signifies that the site default replication level (typically 2) is desired.|@2@|
|group_class|string|Type of group. This does not affect behavior, but determines how the group is presented in the user interface. For example, @project@ indicates that the group should be displayed by Workbench and arv-mount as a project for organizing and naming objects.|@"project"@
null|
|description|text|||
+|properties|hash|User-defined metadata, may be used in queries using "subproperty filters":{{site.baseurl}}/api/methods.html#subpropertyfilters ||
|writable_by|array|List of UUID strings identifying Users and other Groups that have write permission for this Group. Only users who are allowed to administer the Group will receive a full list. Other users will receive a partial list that includes the Group's owner_uuid and (if applicable) their own user UUID.||
|trash_at|datetime|If @trash_at@ is non-null and in the past, this group and all objects directly or indirectly owned by the group will be hidden from API calls. May be untrashed.||
|delete_at|datetime|If @delete_at@ is non-null and in the past, the group and all objects directly or indirectly owned by the group may be permanently deleted.||