The buffer consists of an array of strings (PSZ), the number of which is given by cItems. Each string contains one line of text that can be 0 to 80 characters long. The port name and port description is not required; the Workplace Shell can retrieve these from the OS2SYS.INI file.

The maximum size of the data returned is 4KB. If the buffer is too small, the error code, ERROR_INSUFFICIENT_BUFFER, is returned.