OpenClinica supports user-defined CRF Item Data values according to Item Data properties defined during CRF and Study design. OpenClinica enforces strict data typing corresponding with the Item Datatype. Each data value must conform to the canonical format for its data type. If a value with an invalid data type is inserted or updated, it must be rejected and an exception thrown. This document describes data typing for user-defined CRF Item Data values in OpenClinica version 3.1.