If a header with the same name already exists in the request, OVERWRITE will overwrite the value, APPEND will append to the existing value, or SKIP will keep the existing value.
The case-insensitive name of the header. This name must be unique across transformation policies.
A list of new values. Each value can be a constant or may include one or more expressions enclosed within ${} delimiters.
Set will add a new header if it was not in the original request. If the header already exists on the request, you can choose to override, append, or skip it.