+<strong>unclasses</strong>:
+> Most classes have an unclass, formed by prefixing "un" to the name. For
+> example, -c help has the unclass -c unhelp. The unclass is generally used for
+> snarky or unproductive replies; the prototypical example that first inspired
+> their creation was telling somebody with computer issues to run
+> `sudo rm -rf /`. Rarely, un- prefixes are stacked for even snarkier
+> discussion, on -c ununhelp and so on.
+
+<strong>.d classes</strong>:
+> Classes like -c help.d are sometimes used for discussions that deviate from
+> the conversation on the main class. .d instances are more common, though;
+> see below.
+