This Interim Standard covers implementation of electronic messages for exchange of information on drug prescriptions in the community and hospital environment using the Health Level Seven (HL7) Version 2.5 protocol.This Interim Standard does not deal with commercial transactions with suppliers.This Interim Standard provides consistent use of data definitions as well as commentary and references to the International Organization for Standardization (ISO) and the National Health Data Dictionary.For the purposes of this Interim Standard, only human patients are considered.