What graffiti is is on the wall at the site of St. Peter's grave?

Answer 1

There is quite a bit of graffiti on the wall next to St. Peter's grave. This is from the Vatican Necropolis website, wall G by the bones of St. Peter:

This structure is perpendicular to the red wall, built on the right-hand side (north) of the trophy of Gaius during the second half of the 3rd century. The wall gets its name from the surprising amount of Latin graffiti carved into the plaster by the faithful who visited the tomb of St Peter between the end of the 3rd and the beginning of the 4th centuries.

The graffiti includes names, petitions, Christian symbols of complex interpretation and signs superimposed on one another on the reduced surface of the wall.

In abbreviated form, St Peter's name is present on the wall at least twenty times, usually accompanied by prayers for the dead person named - in one case expressing joy that the lost relative lay in the same cemetery that held Peter's own body. On every part of the wall - freestanding between the letters of a name, formed from or engrafted onto existing lines - there occurred the initials PE or PET.