To retrieve or set choice fields, use the choice Value, not the Label.

For example, if you want to retrieve a list of all closed incidents, use the numerical value for Closed, which is 7 by default.

<state>7</state>
To see a list of choice values:
  1. Navigate to the form containing the choice field. For example, navigate to Incident > Open and select an incident.
  2. Right-click the choice value field and select Configure Dictionary. For example, configure the dictionary for the State field.
  3. From the Choices related list, note the value for the label you want to query. For example, note that the Closed choice has a value of 7.
incident stat value