FDA Final Guidance: Form and Content of the Unique Device Identifier (UDI) The document is intended to assist labelers and FDA-accredited issuing agencies in complying with unique device identifier (UDI) labeling requirements, including by clarifying FDA’s interpretation of certain requirements under 21 CFR 801.40. This content was submitted directly to this website by the supplier. Jul 10th, 2021 The 8-page document describes the requirements for and FDA’s recommendations regarding the form and content of the UDI to help ensure that the UDIs developed under systems for the issuance of UDIs meet the objectives of the Unique Device Identification System Final Rule, 78 FR 58786 (September 24, 2013) (UDI Rule).