- Kinkel, R.J. (2008), Cinderella Church: the Story of Early Christianity, introduction: "In the old days (1950s) these people would be called backsliders, apostates, lapsed Christians, and now this label has emerged: FARC, ie fallen away Roman Catholic."
- Barbernitz, P. (1993), Parish Ministry for Returning Catholics, p3, "'I'm Catholic' is also the statement frequently used by some other people — those whom others might have named 'inactive' Catholics, 'fallen-away' or 'lapsed' Catholics. For many of them, the statement remains, 'I'm Catholic.'"
- Beal, J.P., New Commentary on the Code of Canon Law, "Once a Catholic by baptism or reception, one always remains a Catholic (semel catholicus semper catholicus). Even those who have joined another religion, have become atheists or agnostics, or have been excommunicated remain Catholics. Excommunicates lose rights, such as the right to the sacraments, but they are still bound to the obligations of the law; their rights are restored when they are reconciled through the remission of the penalty."
- Reese, Thomas (2011), The hidden exodus: Catholics becoming Protestants, National Catholic Reporter