This case-sensitive code system http://cdc.gov/nchs/nvss/fhir/vital-records-messaging/CodeSystem/VRM-MessageHeaderURI-cs defines the following codes:

Code	Display	Definition
http://nchs.cdc.gov/vrdr_submission	VRDR Submission	Indicates that the payload is aninitial (or retransmission of an unacknowledged) submission of a VRDR Death Certificate Document
http://nchs.cdc.gov/vrdr_submission_update	VRDR Update	Indicates this is an update to a previously acknowledged submission of a VRDR DeathCertificate Document
http://nchs.cdc.gov/vrdr_submission_void	VRDR Void	Indicates this is void of a VRDR DeathCertificate Document
http://nchs.cdc.gov/vrdr_acknowledgement	VRDR Acknowledgement	Indicates this is an acknowledgement
http://nchs.cdc.gov/vrdr_demographics_coding_update	VRDR Demographics Coding Update	Indicates that this is an updated demographics coding
http://nchs.cdc.gov/vrdr_causeofdeath_coding_update	VRDR Cause of Death Coding Update	Indicates that this is an updated cause of death coding
http://nchs.cdc.gov/vrdr_demographics_coding	VRDR Demographics Coding	Indicates that this is an initial demographics coding
http://nchs.cdc.gov/vrdr_causeofdeath_coding	VRDR Cause of Death Coding	Indicates that this is an initial cause of death coding
http://nchs.cdc.gov/vrdr_alias	VRDR Alias	Indicates that this is an alias for a previously submitted Decedent
http://nchs.cdc.gov/vrdr_extraction_error	VRDR Extraction Error	Indicates that this is an extraction error
http://nchs.cdc.gov/vrdr_status	VRDR Status	Indicates that this is a status for a previously submitted Decedent