Autotype

To have Autotype option in mainframes -
Type Start 3.4 in the command window
Type Keys in the command window and press enter
Set any PF key to AUTOTYPE and press F3 to save the options

Type any dataset name partially and press the PF key assigned :)
press the PF key again to check for other dataset names that can exist

This option will not work for GDG's and VSAM's