This xkcd comic shows a Unix manual page, i.e. a man page (hence the title), for a fictional program called "blerp". Unix man pages are meant to provide a brief reference on the usage of a command, not extended explanations with tutorials as may be found in many hardcopy product manuals. Unfortunately, some Unix commands tend to be very bloated and include lots of optional behavior that is often irrelevant to the original intent of the command and can be done much more easily using shell features like piping and redirection, and thus the manpage grows to explain all of the features. This example exaggerates the obscurity and terseness found in many man pages, making fun of the typical style of the genre.