anchor.diff:  
   ### <a id="requirements-reference"></a> Selector Requirement Reference
   
  +The following table describes how to form selector requirements: 
  +
   <table>
   <tr>
   <th>Requirement</th>
  
positive.code: </pre>
  
  ### <a id="annotation"></a> Add an Annotation
  
  1. To add an annotation to an object, run the following command:
  
  
negative.code: 
  ## <a id="query"></a> List Objects by Querying Labels
  
  The following procedure describes how to list objects by querying label metadata:
  
  1. To query an object by using the `label_selector` parameter on its list endpoint, run the following command: 
  
      ```
  