Acceptance

1. Hosts and templates will support optional list of tags
   1. Host prototypes will not support tags
2. Host and template-level tags will work the same way as macros, i.e. no actual copy of tags is performed when linking a host to templates
3. Еvent will inherit all tags from all hosts of the trigger expression
   1. Event will not have identical tags (same tag + value), they will be combined into one 
4. Front-end improvements
   1. Configuration→Templates
      1. display tag names in the list; max 3 tags; display everything on mouse-over
         1. Tags will be displayed and filtered as they are, i.e. not expanded
      2. filtering by tags, same as under Configuration→Triggers (AND/OR conditions, multiple tags)
         1. filtering must not use inherited tags
      3. Add 'mass update' action with corresponding API method and with the following mass action options supported:
         1. "Host groups" with sub-options "Add", "Replace" and "Remove"
         2. "Description"
         3. "Tags" with sub-options "Add", "Replace" and "Remove"
         4. "Link templates"
      4. when viewing single Template:
         1. Implement two modes (Template tags | Inherited and template tags) of showing tags there just like in Macros tab now. Inherited tags are shown upon request.
            1. Provide the link to template this tag is inherited from
            2. If there is more than one instance of identical tag (e.g. inherited from template A + inherited from template B + normal tag) - it must be possible to see that
   2. Configuration→Hosts
      1. display tag names in the list; max 3 tags; display everything on mouse-over
         1. Tags will be displayed and filtered as they are, i.e. no macros expanded
      2. filtering by tags, same as under Configuration→Triggers (AND/OR conditions, multiple tags)
         1. filtering must not use inherited tags
      3. replace host group related actions with "Host groups" with sub-options "Add", "Replace" and "Remove"
      4. mass action "Tags" with sub-options "Add", "Replace" and "Remove"
      5. when viewing single Host (or host discovered from host prototype):
         1. Implement two modes (Host tags | Inherited and host tags) of showing tags there just like in Macros tab now. Inherited tags are shown upon request.
            1. "Host tags" mode will be disabled for discovered hosts, inherited tags will be displayed
            2. Provide the link to template this tag is inherited from
            3. If there is more than one instance of identical tag (e.g. inherited from template A + inherited from template B + normal tag) - it must be possible to see that
   3. Inherited tags will NOT be displayed in the list of hosts and templates, only normal tags will be shown
      1. How tag filtering works must be explicitly documented
   4. Configuration → Triggers (and Trigger prototypes)
      1. Add 'mass update' action with corresponding API method and with the following mass action options supported:
         1. "Tags" with sub-options "Add", "Replace" and "Remove" (Instead of "Replace tags")
      2. when editing single Trigger (and Trigger prototype):
         1. Implement two modes (Trigger tags | Inherited and trigger tags) of showing tags there just like in Macros tab now. Inherited tags are shown upon request.
            1. Provide the link to template this tag is inherited from
            2. If there is more than one instance of identical tag (e.g. inherited from template A + inherited from template B + normal tag) - it must be possible to see that
5. The following macros will be supported for template and host tags
   1. User macros
   2. {INVENTORY.*}
   3. {HOST.HOST}, {HOST.NAME}, {HOST.CONN}, {HOST.DNS}, {HOST.IP}, {HOST.PORT} and {HOST.ID}
6. Macros used in template and host tags will be resolved on host level, then they are merged with resolved triggers tags and the result is added to the trigger events
7. Zabbix API and XML import/export must be extended to support new functionality

Use cases

1. Management of service names on host level
   1. Add a new tag to a host, for example, Service = Jira
   2. All problems generated by the host triggers will contain tag Service = Jira
2. Management of tags on template level
   1. Add a new tag to a template, for example, App = MySQL
   2. All hosts inherited from the template will contain tag App = MySQL
   3. All problems generated by the triggers of these hosts will contain tag App = MySQL
3. Hosts/template configuration page: Quickly find out from which template the inherited tag came.
4. Trigger configuration page: Quickly find out which tags will be generated in problems coming from this trigger