The character "*" identifies a generic device type, based on which DASD are defined at your installation. Use the generic device type when you have the same use attribute and the same mount attributes regardless of the device you want the volumes mounted on.
If you specify a generic volume serial number, you can specify a generic device type. For example, if you specify the generic volume serial as TSO*, the matching volume serial numbers for this are TSO01, TSO, and TSO123, as above. TSO01 is on a 3350, TSO is on a 3380, and TSO123 is on a 3390. If you want to specify the same mount and use attributes for these volumes, regardless of the device types, you can specify a generic device type and then the mount and use attributes.