The offset is such that the bars need to be oriented left/right. Once left and right is determined, they can go in either end, although the factory put them with the embossed part #s in the fixed anchor.
However, this offset is only on smaller diameter bars so that can generate a certain amount of pre-load in them when installed. As the diameter increases, the need for this pre-load, and thus the offset, is reduced because of the higher rates. This is why on small diameter bars, you need to remove the upper control arm bumper to get enough suspension drop to insert the hexes properly. By contrast, a 1.24 bar needs to be installed at nearly ride height for the hexes to align.