Checks whether the device name you specified is a valid port. If the port name contains special characters, such as a slash (/), or if it contains lowercase letters that you want to preserve, you must enclose the port name within quotation marks (" "). Be aware that anything within quotation marks is written literally to the ALF database file. For example, if the actual port name contains uppercase letters as well as special characters, be sure to specify uppercase letters within the quotation marks. Otherwise, a mismatch will occur between the actual port name and what is specified in the SYSALF.DAT file.