An ancient mode of writing, in alternate directions, one line from left to right, and the next from right to left (as fields are plowed), as in early Greek and Hittite.
Writing "as the ox plows", that is alternating between left to right and right to left. Early alphabets (Old Canaanite, and the very early greek writings (and, surprisingly, fuþark)) used this. Often the right to left glyphs would be mirrors of the left to right ones.
Writing with alternating tines written in opposite directions; one line is written from left to right, then the next line's letters are reversed, written from right to left.