+Example UUID: @zzzzz-4zz18-0123456789abcde@
+
+h2. Resource
+
+Collections describe sets of files in terms of data blocks stored in Keep. See "storage in Keep":{{site.baseurl}}/api/storage.html for details.
+
+Each collection has, in addition to the "Common resource fields":{{site.baseurl}}/api/resources.html:
+
+table(table table-bordered table-condensed).
+|_. Attribute|_. Type|_. Description|_. Example|
+|name|string|||
+|description|text|||
+|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@|
+|replication_confirmed|number|Replication level most recently confirmed by the storage system. This field is null when a collection is first created, and is reset to null when the manifest_text changes in a way that introduces a new data block. An integer value indicates the replication level of the _least replicated_ data block in the collection.|@2@, null|
+|replication_confirmed_at|datetime|When replication_confirmed was confirmed. If replication_confirmed is null, this field is also null.||
+
+h3. Conditions of creating a Collection
+
+The @portable_data_hash@ and @manifest_text@ attributes must be provided when creating a Collection. The cryptographic digest of the supplied @manifest_text@ must match the supplied @portable_data_hash@.
+
+h3. Side effects of creating a Collection