<p>You should categorize the operations of your contract with tags. Categorizing operations helps your users understand
  the broad organization of the API and highlights the type of manipulated resources.
</p>

<h2>Noncompliant Code Example (OpenAPI 3)</h2>
<pre>
openapi: "3.0.1"
info:
  version: 1.0.0
  title: Swagger Petstore
tags:
- name: used-tag
  description: a tag referenced in the operations
paths:
  /pets:
    get:
      tags:
      - used-tag
      responses: {}
    post:               # All operations should be tagged
      responses:
        default:
          description: the default response
</pre>
<h2>Compliant Solution (OpenAPI 3)</h2>
<pre>
openapi: "3.0.1"
info:
  version: 1.0.0
  title: Swagger Petstore
tags:
- name: used-tag
  description: a tag referenced in the operations
- name: other-tag
  description: a tag referenced in the operations
paths:
  /pets:
    get:
      tags:
      - used-tag
      - other-tag
      responses: {}
    post:
      tags:
      - other-tag
      responses:
        default:
          description: the default response
</pre>