| Code | Description | Comment | Version |
| ACK | General acknowledgment message | 2 | from v2.1 |
| ADR | ADT response | 3 - Deprecated | added v2.2 |
| ADT | ADT message | 3 | added v2.2 |
| ARD | Ancillary RPT (display) (for backward compatibility only) | deprecated | from v2.1, removed after v2.3.1 |
| BAR | Add/change billing account | 6 | from v2.1 |
| BPS | Blood product dispense status message | 4 | added v2.5 |
| BRP | Blood product dispense status acknowledgement message | 4 | added v2.5 |
| BRT | Blood product transfusion/disposition acknowledgement message | 4 | added v2.5 |
| BTS | Blood product transfusion/disposition message | 4 | added v2.5 |
| CCF | Collaborative Care Fetch | 7 | added v2.7 |
| CCI | Collaborative Care Information | 7 | added v2.7 |
| CCM | Collaborative Care Message | 7 | added v2.7 |
| CCQ | Collaborative Care Referral | 7 | added v2.7 |
| CCU | Collaborative Care Referral | 7 | added v2.7 |
| CNQ | Cancel query | deprecated | added v2.3, removed after v2.3 |
| CQU | Collaborative Care Referral | 7 | added v2.7 |
| CRM | Clinical study registration message | 7 | added v2.3.1 |
| CSU | Unsolicited study data message | 7 | added v2.3 |
| DBC | Create Donor Record | 4 | added v2.8 |
| DBU | Update Donor Record | 4 | added v2.8 |
| DEL | Donor Eligibility | 4 | added v2.8 |
| DEO | Donor Eligibility Observation | 4 | added v2.8 |
| DER | Donor Eligibility Request | 4 | added v2.8 |
| DFT | Detail financial transactions | 6 | added v2.2 |
| DOC | Document response | 9 - Deprecated | added v2.3 |
| DPR | Donation Procedure | 4 | added v2.8 |
| DRC | Donor Request to Collect | 4 | added v2.8 |
| DSR | Display response | 5 - Deprecated | from v2.1 |
| EAC | Automated equipment command message | 13 | added v2.4 |
| EAN | Automated equipment notification message | 13 | added v2.4 |
| EAR | Automated equipment response message | 13 | added v2.4 |
| EDR | Enhanced display response | deprecated | added v2.3, removed after v2.5.1 |
| EHC | Health Care Invoice | 16 | added v2.6 |
| EQQ | Embedded query language query | deprecated | added v2.3, removed after v2.5.1 |
| ERP | Event replay response | deprecated | added v2.3, removed after v2.5.1 |
| ERQ | Event replay query | deprecated | added v2.3, removed after v2.3 |
| ESR | Automated equipment status update acknowledgment message | 13 | added v2.4 |
| ESU | Automated equipment status update message | 13 | added v2.4 |
| INR | Automated equipment inventory request message | 13 | added v2.4 |
| INU | Automated equipment inventory update message | 13 | added v2.4 |
| LSR | Automated equipment log/service request message | 13 | added v2.4 |
| LSU | Automated equipment log/service update message | 13 | added v2.4 |
| MCF | Delayed Acknowledgment (Retained for backward compatibility only) | deprecated | from v2.1, removed after v2.5.1 |
| MDM | Medical document management | 9 | added v2.3 |
| MFD | Master files delayed application acknowledgment | 8 - Deprecated | added v2.2 |
| MFK | Master files application acknowledgment | 8 | added v2.2 |
| MFN | Master files notification | 8 | added v2.2 |
| MFQ | Master files query | 8 - Deprecated | added v2.3 |
| MFR | Master files response | 8 - Deprecated | added v2.2 |
| NMD | Application management data message | 14 | added v2.2 |
| NMQ | Application management query message | 14 - Deprecated | added v2.2 |
| NMR | Application management response message | 14 - Deprecated | added v2.2 |
| OMB | Blood product order message | 4 | added v2.5 |
| OMD | Dietary order | 4 | added v2.4 |
| OMG | General clinical order message | 4 | added v2.4 |
| OMI | Imaging order | 4 | added v2.5 |
| OML | Laboratory order message | 4 | added v2.4 |
| OMN | Non-stock requisition order message | 4 | added v2.4 |
| OMP | Pharmacy/treatment order message | 4 | added v2.4 |
| OMQ | General order message with document payload | 4 | added v2.8 |
| OMS | Stock requisition order message | 4 | added v2.4 |
| OPL | Population/Location-Based Laboratory Order Message | 4 | added v2.6 |
| OPR | Population/Location-Based Laboratory Order Acknowledgment Message | 4 | added v2.6 |
| OPU | Unsolicited Population/Location-Based Laboratory Observation Message | 7 | added v2.6 |
| ORA | Observation Report Acknowledgment | 7 | added v2.7 |
| ORB | Blood product order acknowledgement message | 4 | added v2.5 |
| ORD | Dietary order acknowledgment message | 4 | added v2.4 |
| ORF | Query for results of observation | 7 - Deprecated | from v2.1 |
| ORG | General clinical order acknowledgment message | 4 | added v2.4 |
| ORI | Imaging order acknowledgement message | 4 | added v2.5 |
| ORL | Laboratory acknowledgment message (unsolicited) | 7 | added v2.4 |
| ORM | Pharmacy/treatment order message | 4 - Deprecated | from v2.1 |
| ORN | Non-stock requisition - General order acknowledgment message | 4 | added v2.4 |
| ORP | Pharmacy/treatment order acknowledgment message | 4 | added v2.4 |
| ORR | General order response message response to any ORM | 4 - Deprecated | from v2.1 |
| ORS | Stock requisition - Order acknowledgment message | 4 | added v2.4 |
| ORU | Unsolicited transmission of an observation message | 7 | from v2.1 |
| ORX | General Order Message with Document Payload Acknowledgement | 4 | added v2.8 |
| OSM | Specimen Shipment Message | 7 | added v2.7 |
| OSQ | Query response for order status | 4 - Deprecated | from v2.1 |
| OSR | Query response for order status | 4 - Deprecated | added v2.3 |
| OSU | Order status update | 4 | added v2.8 |
| OUL | Unsolicited laboratory observation message | 7 | added v2.4 |
| PEX | Product experience message | 7 | added v2.3 |
| PGL | Patient goal message | 12 | added v2.3 |
| PIN | Patient insurance information | 11 | added v2.3 |
| PMU | Add personnel record | 15 | added v2.4 |
| PPG | Patient pathway message (goal-oriented) | 12 | added v2.3 |
| PPP | Patient pathway message (problem-oriented) | 12 | added v2.3.1 |
| PPR | Patient problem message | 12 | added v2.3 |
| PPT | Patient pathway goal-oriented response | Deprecated | added v2.3 |
| PPV | Patient goal response | Deprecated | added v2.3 |
| PRR | Patient problem response | Deprecated | added v2.3 |
| PTR | Patient pathway problem-oriented response | Deprecated | added v2.3 |
| QBP | Query by parameter | 5 | added v2.4 |
| QCK | Query general acknowledgment | 5 - Deprecated | added v2.3 |
| QCN | Cancel query | 5 | added v2.4 |
| QRY | Query, original mode | 3 | added v2.2 |
| QSB | Create subscription | 5 | added v2.4 |
| QSX | Cancel subscription/acknowledge message | 5 | added v2.4 |
| QVR | Query for previous events | 5 | added v2.4 |
| RAR | Pharmacy/treatment administration information | 4 - Deprecated | added v2.2 |
| RAS | Pharmacy/treatment administration message | 4 | added v2.2 |
| RCI | Return clinical information | 11 | added v2.3 |
| RCL | Return clinical list | 11 | added v2.3 |
| RDE | Pharmacy/treatment encoded order message | 4 | added v2.2 |
| RDR | Pharmacy/treatment dispense information | 4 | added v2.2 |
| RDS | Pharmacy/treatment dispense message | 4 | added v2.2 |
| RDY | Display based response | 5 | added v2.4 |
| REF | Patient referral | 11 | added v2.3 |
| RER | Pharmacy/treatment encoded order information | 4 - Deprecated | added v2.2 |
| RGR | Pharmacy/treatment dose information | 4 - Deprecated | added v2.2 |
| RGV | Pharmacy/treatment give message | 4 | added v2.2 |
| ROC | Request clinical information | deprecated | added v2.3, removed after v2.3 |
| ROD | Request pateint demographics | deprecated | added v2.3, removed after v2.3 |
| ROR | Pharmacy/treatment order response | 4 - Deprecated | added v2.2 |
| RPA | Return patient authorization | 11 | added v2.3 |
| RPI | Return patient information | 11 | added v2.3 |
| RPL | Return patient display list | 11 | added v2.3 |
| RPR | Return patient list | 11 | added v2.3 |
| RQA | Request patient authorization | 11 | added v2.3 |
| RQC | Request clinical information | 11 | added v2.3 |
| RQI | Request patient information | 11 | added v2.3 |
| RQP | Request patient demographics | 11 | added v2.3 |
| RQQ | Event replay query | deprecated | added v2.3.1, removed after v2.5.1 |
| RRA | Pharmacy/treatment administration acknowledgment message | 4 | added v2.2 |
| RRD | Pharmacy/treatment dispense acknowledgment message | 4 | added v2.2 |
| RRE | Pharmacy/treatment encoded order acknowledgment message | 4 | added v2.2 |
| RRG | Pharmacy/treatment give acknowledgment message | 4 | added v2.2 |
| RRI | Return referral information | 11 | added v2.3 |
| RSP | Segment pattern response | 5 | added v2.4 |
| RTB | Tabular response | 5 | added v2.4 |
| SCN | Notification of Anti-Microbial Device Cycle Data | 17 | added v2.6 |
| SDN | Notification of Anti-Microbial Device Data | 17 | added v2.6 |
| SDR | Sterilization anti-microbial device data request | 17 | added v2.6 |
| SIU | Schedule information unsolicited | 10 | added v2.3 |
| SLN | Notification of New Sterilization Lot | 17 | added v2.6 |
| SLR | Sterilization lot request | 17 | added v2.6 |
| SMD | Sterilization anti-microbial device cycle data request | 17 | added v2.6 |
| SPQ | Stored procedure request | deprecated | added v2.3, removed after v2.5.1 |
| SQM | Schedule query message | 10 - Deprecated | added v2.3 |
| SQR | Schedule query response | 10 - Deprecated | added v2.3 |
| SRM | Schedule request message | 10 | added v2.3 |
| SRR | Scheduled request response | 10 | added v2.3 |
| SSR | Specimen status request message | 13 | added v2.4 |
| SSU | Specimen status update message | 13 | added v2.4 |
| STC | Notification of Sterilization Configuration | 17 | added v2.6 |
| STI | Sterilization item request | 17 | added v2.6 |
| SUR | Summary product experience report | 7 - Deprecated | added v2.3.1 |
| TBR | Tabular data response | 5 - Deprecated | added v2.3 |
| TCR | Automated equipment test code settings request message | 13 | added v2.4 |
| TCU | Automated equipment test code settings update message | 13 | added v2.4 |
| UDM | Unsolicited display update message | 5 | from v2.1 |
| VQQ | Virtual table query | deprecated | added v2.3, removed after v2.5.1 |
| VXQ | Query for vaccination record | 4 - Deprecated | added v2.3 |
| VXR | Vaccination record response | 4 - Deprecated | added v2.3 |
| VXU | Unsolicited vaccination record update | 4 | added v2.3 |
| VXX | Response for vaccination query with multiple PID matches | 4 -Deprecated | added v2.3 |