Are Arrow Stones in Churches a Real Thing?

The story of arrow stones is again a very, very ubiquitous one that almost every village in the country will have its medieval church surviving. The stories are usually trotted out that this is the result of archery practice, which was made mandatory by Edward III in the mid 14th century. So it seems to be linked to a localized national tradition of storytelling rather than an archaeological reality. Do we know what those marks might be?