Attempting to publish a metadata document to an ArcIMS Metadata service produces the following error from ArcCatalog:
"1 metadata documents could not be published to the target location due to invalid content".
The error usually references a specific problem element, such as 'Valid publisher is required' or 'Data theme value is not a valid string'.
The ArcIMS Metadata service has validation turned on. Validation is a setting within ArcIMS Metadata service that checks for five key metadata elements and whether or not they are entered correctly. Without these elements referenced correctly, the document does not pass validation and cannot be published. This check helps to ensure quality metadata documents are published to the service.
A complete list of content types with codes are available on page 44 of the 'Creating Metadata Services' PDF.