We could take the FreeBSD approach which is:
%Hd major device number in decimal (st_dev)
%Ld minor device number in decimal (st_dev)
%Hr major device type in decimal (st_rdev)
%Lr minor device type in decimal (st_rdev)
Note I'd be inclined to not have a space between major,minor in default stat
output,
as there should be no ambiguity with locale formatted numbers, which could be
the case with ls. For example, my ls alias uses thousands grouping with:
alias ls="BLOCK_SIZE=\'1 ls --color=auto".
I.e. the default format would from stat would be
Device: %Hd,%Ld ..... Device type: %Hr,%Lr
For consistency if we provided the above we should also probably provide:
%r (composed) device type in decimal (st_rdev)
%R (composed) device type in hex (st_rdev)