# Metadata Requirements

Metadata Requirements are explicitly outlined in the HTAN Phase 2 Data Model (Metadata) Documentation. This documentation is directly linked to the underlying github repository code and will be updated as additional assays are added to the Phase 2 Data Model. HTAN Phase 2 Data Model (Metadata) Documentation includes attribute descriptions, requirements and valid values. Metadata is submitted to HTAN via Synapse which is developed and maintained by Sage Bionetworks.

General requirements include the following:

All assay data must be linked to their respective HTAN participants and biospecimens. If an assay file cannot be linked to validated participant demographic and biospecimen records, it will trigger an error when the HTAN DCC prepares data for data release.
A participant must only have one demographics record. Duplicate HTAN Participant ID records will trigger an error. Other clinical metadata also have restrictions in the number of records per participant. Please see Phase 2 Clinical Data for more information.

Terminology Alert

In the Synapse system, metadata can be File-based (associated with a data file) or Record-based. Please see Synapse's Documentation for more information about these terms.

For HTAN:
Record-based metadata includes the Clinical and Biospecimen modules of the HTAN2 Data Model.
File-based metadata includes all other modules in the HTAN2 Data Model.