When creating a web service procedure using the CREATE PROCEDURE statement, if you specify an HTTP HEADER name with no colon (:) and no value, the HTTP client application suppresses the header. If you include a colon but do not provide a value, the HTTP client application includes the header name, but no value. For example:

CREATE PROCEDURE suds(...)
TYPE 'SOAP:RPC'
URL '...'
HEADER 'SOAPAction\nDate\nFrom:';

In this example, the Action and Date HTTP headers, which are automatically generated by SQL Anywhere, are suppressed, and the From header is included but with no value.

Modifying automatically generated headers, can have unexpected results. The following HTTP headers are typically automatically generated and should not be modified without very careful consideration.