This case-sensitive code system http://hl7.org/fhir/us/ndh/CodeSystem/NdhDirectTrustEndpointUsecaseCS defines the following codes:

Code	Display	Definition
payer-payer-data-exchange	information exchange between payers	information exchange between payers
payer-provider-data-exchange	information exchange between payers and providers	information exchange between payers and providers
payer-patient-data-exchange	information exchange between payers and patients	information exchange between payers and patients
provider-provider-data-exchange	information exchange between providers	information exchange between providers
provider-payer-data-exchange	information exchange between providers and payers	information exchange between providers and payers
provider-to-patient-data-exchange	information exchange between providers and patients	information exchange between providers and patients
patient-payer-data-exchange	information exchange between patients and payers	information exchange between patients and payers
patient-provider-data-exchange	information exchange between patients and providers	information exchange between patients and providers
patient-public-health-data-exchange	information exchange between patients and public health	information exchange between patients and public health
patient-research-data-exchange	information exchange between patients and research	information exchange between patients and research
public-health-patient-data-exchange	information exchange between public health and patients	information exchange between public health and patients
research-patient-data-exchange	information exchange between research and patients	information exchange between research and patients
patient-access	information exchange for patients	information exchange for patients
care-case-manager	information exchange with a care or case managers	information exchange with a care or case managers
care-coordination	information exchange for care coordination across the entire patient care team	information exchange for care coordination across the entire patient care team
advanced-eob	information exchange for advanced eobs	information exchange for advanced eobs
coverage-requirements-discovery-crd	information exchange for discovering coverage requirements	information exchange for discovering coverage requirements
documentation-templates-rules-dtr	information exchange for documentation templates and rules	information exchange for documentation templates and rules
prior-authorization	information exchange for prior authorization	information exchange for prior authorization
formulary	information exchange for drug formulary	information exchange for drug formulary
prescriptions	information exchange for prescriptions	information exchange for prescriptions
item-service-price-transparency	information exchange for item or service price transparency	information exchange for item or service price transparency
patient-cost-transparency-gfe	information exchange for making patient costs transparent	information exchange for making patient costs transparent
quality-measure-reporting	information exchange for quality measure reporting	information exchange for quality measure reporting
adverse-event-reporting	information exchange for adverse event reporting	information exchange for adverse event reporting
notifications	information exchange for notifications	information exchange for notifications
adt-notifications	information exchange for ADT notifications	information exchange for ADT notifications
scheduling	information exchange for scheduling	information exchange for scheduling
release-of-information	information exchange for release of information	information exchange for release of information
medical-records	information exchange for medical records	information exchange for medical records
administrative	information exchange for administrative activities	information exchange for administrative activities
support	information exchange for technical or customer support activities	information exchange for technical or customer support activities
billing	information exchange for billing	information exchange for billing
referrals	information exchange for referrals	information exchange for referrals
transfer-transition-of-care	information exchange for transfers and transitions of care	information exchange for transfers and transitions of care
provider-directory	information exchange for directory maintenance and quality	information exchange for directory maintenance and quality
care-plans-review-or-approval	information exchange to support care plan review and approval	information exchange to support care plan review and approval
public-health-reporting	information exchange for public health reporting	information exchange for public health reporting
payers-and-payments	information exchange for billing	information exchange for billing
break-the-glass	information exchange that requires break the glass	information exchange that requires break the glass
individual-practitioner	information exchange with an individual provider	information exchange with an individual provider
individual-patient-member-consumer	information exchange with an individual patient-member-client-consumer	information exchange with an individual patient-member-client-consumer
location	information exchange with a treating facility	information exchange with a treating facility
group	information exchange with a provider group	information exchange with a provider group
department	information exchange with a provider department	information exchange with a provider department
no-reply	endpoint does not accept information for exchange	endpoint does not accept information for exchange
any-all	endpoint that accepts any and all types of information exchange possible for its endpoint type	endpoint that accepts any and all types of information exchange possible for its endpoint type