I'm going to disagree with this statement " There is usually a maximum of 4 persons allowed in a standard private grave." Whilst this may be the case some places, in rural Ireland it doesn't apply. Family plots can be used over and over again depending on factors such as how deep the first grave(s) dug, condition of ground, how long ago last interment. Unfortunately it is often the case that all the people buried in a particular plot have not been recorded on the headstone (if there is actually a headstone). Another problem is that many churches here did not actually keep a record of burials.