I have taken an interest in Webmentions for a non-New Leaf Journal project. In order to learn about the protocol, I installed the Webmention plugin by Mr. Matthias Pfefferle. I ran into an issue getting everything working. Webmentions require pingbacks to be enabled. I disabled pingbacks at some point in the past. I was confused after re-enabling pingbacks why webmentions were working for my old posts but not my most recent posts. Was it caching? My caching plugin was in the middle of a full website cache when I installed the plugin. However, I realized that when I enabled pingbacks, pingbacks were only enabled prospectively. Thus, I had to go back and, one by one, enable pingbacks on posts. I feared this would be a terrible process – but as luck would have it, I disabled pingbacks in January shortly after our site move.  All’s well that ends well.