If the buffer is too small to hold even one data structure, the error code ERROR_INSUFFICIENT_BUFFER, is returned. If there is more data, ERROR_MORE_DATA is returned and cbRequired gives the size of buffer required to get all the data.

The Workplace Shell is the expected caller of this function and determines which ports to install in OS2SYS.INI. The port descriptions are used to label the icon for each port. The Workplace Shell does not allow the installation of ports that can be serviced by more than one port driver. The first port installed is used. The Workplace Shell does not display other ports for installation. If another port is required, the first port must be uninstalled.