Hi API-WG, Neutron is implementing tag support for network resource [0]. The implementation follows 'Tags' guideline defined by API-WG [1]. I have a questions on the guideline. ---- We can create a tag by PUT'ing an individual tag: What status code should be returned if a requested tag already exists? PUT /servers/1234567890/tags/qux The guideline defines 201 (+ Location header) on success. In the current neutron implementation proposed, 409 is returned when a requested tag already exists. Thanks, Akihiro [0] https://review.openstack.org/#/c/273881 [1] http://specs.openstack.org/openstack/api-wg/guidelines/tags.html