Updated resolution description: The base R4 EOB requires item.productOrService is required when item.revenue is provided.  However, claims submission standards for Inpatient Institutional claims do not necessarily require a line level procedure code as the procedure is submitted at the header level.  To be compliant with cardinality requirements a placeholder value must be provided for item.productOrService.; otherwise, the majority of Inpatient Institutional claims will faile validation.   To remedy, add the value "non-applicable" from the Data Absent Reason Code System to the CPT/HCPCS value within the Inpatient Institutional profile.   Update the notes as follows:   A CPT / HCPCS code may not be available on an inpatient institutional claim. The cardinality of the HL7 base EOB Resource for item.productOrService is 1..1 if .item is provided.  Since .item.revenue is required it means that item.productOrService must be populated.  Since the profile is not able to relax the cardinality of the resource, it is recommended payers provide a missing data value of 'Not Applicable' when a CPT / HCPCS code is not available.