A new draft guidance from the U.S. Food and Drug Administration (FDA) aim to clarify how Unique Device Identifiers (UDIs) are included on medical devices.

“Unique Device Identification System: Form and Content of the Unique Device Identifier (UDI)” offers some detailed definitions of how the UDI has to be presented in both “both easily readable plain-text” and the form which can be transferred to an electronic health record or a computer system, known as automatic identification and data capture (AIDC).

For the text form, the guidance say the device identifier, production identifiers, and the data delimiters have to be included. The actual text of the UDI can be multiple lines, and “should be displayed below or near the AIDC technology form of the UDI.”

The AIDC instructions are a bit more complex. The draft guidance says while a particular AIDC system isn’t required, it does recommend the electronic form of the UDI come in some kind of scannable format, like a bar code. Since physical space on devices may be limited, the guidance allows for these codes to be broken up, such as a separate bar code for the device identifier and another for the production identifier.

Labelers could also include multiple types of scannable codes on a device.

The draft guidance also says the device identifier information should be listed before the production identifier, with any non-UDI information listed after the UDI.

Comments on the guidance will be accepted until September 24.