Individual users may also add their own shortcuts to the .ExifTool_config file in their home directory (or the directory specified by the EXIFTOOL_HOME environment variable). The shortcuts are defined in a hash called %Image::ExifTool::UserDefined::Shortcuts. The keys of the hash are the shortcut names, and the elements are either tag names or references to lists of tag names.
An example shortcut definition in .ExifTool_config:
%Image::ExifTool::UserDefined::Shortcuts = ( MyShortcut => ['createdate','exif:exposuretime','aperture'], MyAlias => 'FocalLengthIn35mmFormat', );
In this example, MyShortcut is a shortcut for the CreateDate, EXIF:ExposureTime and Aperture tags, and MyAlias is a shortcut for FocalLengthIn35mmFormat.