Is it possible to update a hidden field on a form via Web Services?

Question: Is it possible to update a hidden field on a form via Web Services?

Answer: When you update a hidden field on a Standard Form or Custom Form via Web Services. The request would encounter the below error:

"INSUFFICIENT_PERMISSION -  You do not have permissions to set a value for element custom_field_internalid due to one of the

following reasons: 1) The field is read-only; 2) An associated feature is disabled; 3) The field is available either when

a record is created or updated, but not in both cases."

As an alternate solution to this error, you could just use a different custom form that Web Services would use that has the field not set to hidden.