Each line in the file can be a configuration variable, a blank line, or a comment. The value of an variable is assigned by an statement of the form: name=[value]
Configuration options can be broken out into configuration snippets and placed in individual files in the /etc/mkinitramfs/conf.d directory. Files in this directory are always read after the main configuration file, so you can override the settings in the main config file without editing it directly.
most adds most file system, all ide, sata, scsi and usb drivers.
dep tries to guess which modules are necessary for the running box.
netboot adds the base modules, network modules, but skips block devices.
list includes only modules from the additional modules list to load them early.