Screen capture of the table SDETreeNode in OpenSDE. The first row contains the column headers. The first three columns represent references to the patient, event (registration session) and the version of the domain tree. TreeNodePathId refers to the recorded node in the domain tree. The columns that include "val" are used to store values. ValueUnitEnvId refers to the unit of the value. Comment can store free-text. TreeNodeTime refers to the moment to which the observation applies.