The font is called @inpressulum after the twitter name of Marc who wears it on his calf. Its a free interpretation of Gaelic script. The font contains only the characters visible in the artwork. Some of the glyphs where modified to form the horizontal bar of the cross.
The tattoo shows a verse of “The Family Prayer” of the movie The Boondock Saints. Its a translation in the Irish language from the following:
“Never shall innocent blood be shed. Yet the blood of the wicked shall flow like a river. The three shall spread their blackened wings and be the vengeful striking hammer of god.”
The legs of Marc after applying the tattoo on his right calf.