15thc perception on swallowtail merlons?

[Mark Knowles]

I thought it worth mentioning Guelph and Ghibiline flags as a parallel to the battlements.

Guelph flags tended to have yellow fleurs de lys on a blue background and Ghibellines had a black imperial eagle on a yellow background. So one might think that where one sees Guelph flags one might also see Guelph battlements and where one sees Ghibiline flags one might also see Ghibiline battlements.