ISO/IEC 9075-4:2016 specifies the syntax and semantics of a database language for declaring and maintaining persistent database language routines in SQL-server modules.

The database language for <externally-invoked procedure>s and <SQL-invoked routine>s includes:

- The specification of statements to direct the flow of control.

- The assignment of the result of expressions to variables and parameters.

- The specification of condition handlers that allow SQL-invoked routines to deal with various conditions that arise during their execution.

- The specification of statements to signal and resignal conditions.

- The declaration of standing SQL-server cursors.

- The declaration of local variables.

It also includes the definition of the Information Schema tables that contain schema information pertaining to SQL-server modules and SQL-invoked routines.