It didn’t take long to figure out what this does, but I still haven’t figured out the why. Why in the world would anyone need this? Is it one component of a basic abstraction pattern for different implementations of document.write? It’s certainly not easier to type DocumentDotWrite so it couldn’t be a shorthand. This is where context comes into play. The script tag itself is written by a document.write call which is contained within an iframe which is written by a call to document.write which is loaded by another remote script whose tag is written with a call to… take a wild guess.