# Specify the User-Defined Derived Type

This section discusses various aspects of user-defined I/O, such as characteristics of defined I/O procedures and resolving defined I/O procedure references.

Parent topic: User-Defined Derived-Type I/O

- DT Edit Descriptor in User-Defined I/O
- Associate a Procedure with Defined I/O
- Characteristics of Defined I/O Procedures
- Defined I/O Data Transfers
- Resolve Defined I/O Procedure References
- Recursive Defined I/O