Once a system administrator has added an extended stored procedure, users can find out what new functions are available by using the system procedure sp_helpextendedproc. When used without an argument, sp_helpextendedproc displays all extended stored procedures that are currently registered with the master database. If you specify an extended stored procedure name as an argument, sp_helpextendedproc verifies whether that function is currently available.
SQL Server and database clients can use extended stored procedures in the same way as they use standard stored procedures. For example, SQL Server can call an extended stored procedure as the result of a trigger, or a user can issue the EXECUTE command, specifying the name of the extended stored procedure and supplying any parameters required by that extended stored procedure. Both SQL Server and database clients can access extended stored procedures on a remote server by specifying the remote server name when calling the procedure.