byte      ; the same as rb 1
byte [?] ; the same as rb 1
byte [3] ; the same as rb 3
byte [4] 5 ; the same as db 4 dup 5
etc.
    

aligned word
aligned dword [4]
etc.
    

struc aligned? args&
  match =byte?, args
    label .
    byte [1]
  else match =byte? more, args
    label .
    byte more
  else match =word?, args
    align 2
    label .
    word [1]
  else match =word? more, args
    align 2
    label .
    word more
  end match
end struc
    

Is it possible to somehow match only the beginning of the string so that it doesn't matter if 'more' is empty or not?

    match =word? more, args :
        align 2
        label .
        match value :, more
                word value
        else
                word [1]
        end match
    end match