Hi!

Indeed it is: ref as the road number, and local_ref as the segment number.

It is a work in progress for all roads across Wexford; I've taken a break for the moment, but I keep my progress updates on the wiki; the original road schedule and indeed wiki page is quite outdated, but modern data sources are being incorporated: https://wiki.openstreetmap.org/wiki/Ireland/Roads/Wexford.

A great majority of R roads, and many L roads, have been tagged in such a manner: if local_ref is incorrect, please let me know and I shall attempt to rectify those that have been completed and any future updates I shall use the correct tagging -- thank you!