For syslinux this means setting the timeout to 1 in syslinux.cfg.
If you want to change selection, open document below and click on "Move attachment"

B.2.Â Using preseeding
otloader configuration file If you do specify the preconfiguration file in the bootloader configuration, you might change the configuration so you don't need to hit enter to boot the installer. <span>For syslinux this means setting the timeout to 1 in syslinux.cfg. To make sure the installer gets the right preconfiguration file, you can optionally specify a checksum for the file. Currently this needs to be a md5sum, and if specified it must match