+;; These macros may look very much like the ones in GNUS 4.1. They
+;; are, in a way, but you should note that the indices they use have
+;; been changed from the internal GNUS format to the NOV format. The
+;; makes it possible to read headers from XOVER much faster.
+;;
+;; The format of a header is now:
+;; [number subject from date id references chars lines xref extra]
+;;
+;; (That next-to-last entry is defined as "misc" in the NOV format,
+;; but Gnus uses it for xrefs.)
+