Among some Orthodox monastics (and occasionally other faithful), the canonical hours and preparation for Holy Communion may be replaced by praying the Jesus Prayer a specified number of times dependent on the service being replaced. In this way prayers can still be said even if the service books are for some reason unavailable or the person is not literate or otherwise unable to recite the service; the prayer rope becomes a very practical tool in such cases, simply for keeping count of the prayers said. However, among some monastics, e.g. hesychasts, this replacement is the norm.