There is a Latin inscription in the keystone of the arch in the doorway of The Tholsel. 
It reads ” LIBERTATE ASSERTA VICIT VERITAS” and is illustrated in Hore’s History of the Town & County of Wexford (see below).
We tried Google Translate and the result didn’t make sense so we referred it to an expert in this area and she also is scratching her head.
We could suggest what they might have been trying to say but could be wrong.
We popped down to The Tholsel to have a look at the actual keystone but as you can see from the photo, instead of being shrouded in mystery it is covered in mould.