Thanks Gordon! I understand now and coincidentally I bought that book a few weeks ago.

This is not my area of expertise, if, as a broad generalist, I could be said to have any expertise, but I had to research this. The following definitions come from “The Braconid and Ichneumonid Parasitoid Wasps: Biology, Systematics, Evolution and Ecology” by Donald L.J. Quicke.
Antefurcal when the anterior junction of a posterior cross vein is basal to the posterior junction of the cross vein that it is routinely nearly opposite to.
Interstitial when the anterior junction of a posterior cross vein is more or less directly in line with the posterior junction of the cross vein that it is routinely nearly opposite to.
Postfurcal when the anterior junction of a posterior cross vein is distal to the posterior junction of the cross vein that it is routinely nearly opposite to.

For wing venation, I am struggling with the following terms. Could you please add them and the definition relating to venation?

Antefurcal, postfurcal and interstitial.

Thank you for your suggestions, I will add them to my ‘to do’ list.

Suggestions: For unusual endings, include the pleural ending.