"There is no one statement that can be applied to all Quakers -- including that one," a Quaker said during a presentation on the Society of Friends. In the case of their graves, the customs have changed over time and distance.
In the oldest part of the Sandy Spring Friends graveyard, the graves are unmarked. We were told that the early graves were "marked" with pieces of fieldstone and the locations noted in the meeting house records. When it was proposed in the mid-19th century that actual carved gravestones be put in place, one angry elder removed all the field stones and burned the records in his keeping, thus "protecting" the dearly departed from identification of the future generations.
In nearby Woodside Cemetery graves of the same era reveal another Quaker trait -- the number system of dates to avoid using the old "heathen" names. So, April 18, 1853 becomes 4 mo. 18th, 1853.