Custom Forms API
XNAT 1.8.8 introduced the concept of Custom Forms as a dynamic, portable means of defining new searchable fields for a given data type. Site Administrators have the ability to design, implement, and fully manage the lifecycle of these forms, including disabling if desired. See: Custom Forms Administration.
This feature becomes even more powerful in XNAT 1.10.0 when paired with Dynamic Data Types. See: Adding a Dynamic Data Type.
Custom form values are stored in custom fields, which can also be managed via their own API endpoints. See: Custom Fields API.
(Open API documentation is only available to view online)