| 1 | SM | STUDYID | Study Identifier | Char | | Identifier | Req | Unique identifier for a study. |
| 2 | SM | DOMAIN | Domain | Char | | Identifier | Req | Two-character abbreviation for the domain. |
| 3 | SM | USUBJID | Unique Subject Identifier | Char | | Identifier | Req | Identifier used to uniquely identify a subject across all studies. |
| 4 | SM | SMSEQ | Sequence Number | Num | | Identifier | Req | Sequence number to ensure uniqueness of subject records. Should be assigned to be consistent chronological order. |
| 5 | SM | MIDS | Disease Milestone Instance Name | Char | | Topic | Req | Name of the specific Disease Milestone. For types of Disease Milestone that can occur multiple times, the name will end with a sequence number. Example: "HYPO1". |
| 6 | SM | MIDSTYPE | Disease Milestone Type | Char | | Record Qualifier | Req | The type of Disease Milestone. Example: "HYPOGLYCEMIC EVENT". |
| 7 | SM | SMSTDTC | Start Date/Time of Milestone | Char | ISO 8601 | Timing | Exp | State date/time of Milestone Instance, if Milestone is an intervention or event, or date of Milestone if Milestone is a finding. |
| 8 | SM | SMENDTC | End Date/Time of Milestone | Char | ISO 8601 | Timing | Exp | End date/time of Disease Milestone Instance. |
| 9 | SM | SMSTDY | Study Day of Start of Milestone | Num | | Timing | Exp | Study day of start of Disease Milestone Instance, relative to the sponsor-defined RFSTDTC. |
| 10 | SM | SMENDY | Study Day of End of Milestone | Num | | Timing | Exp | Study day of end of Disease Milestone Instance, relative to the sponsor-defined RFSTDTC. |