From `man 8 mount` on Linux:
> If no `-t` option is given, or if the `auto` type is specified, mount will try to guess the desired type. Mount uses the `blkid` library for guessing the filesystem type; if that does not turn up anything that looks familiar, mount will try to read the file `/etc/filesystems`, or, if that does not exist, `/proc/filesystems`. All of the filesystem types listed there will be tried, except for those that are labeled `nodev` (e.g. `devpts`, `proc` and `nfs`). If `/etc/filesystems` ends in a line with a single `*`, `mount` will read `/proc/filesystems` afterwards. While trying, all filesystem types will be mounted with the mount option `silent`.
So just create a file `/etc/filesystems` containing something like this:
ext4
ext3
ext2
vfat
msdos
ntfs
iso9660
ufs
xfs
Add more filetypes if you need. Then you can use type `auto` in `fstab`.