tagline

The following tagline appears at the top of the xkcd main page, regardless of which comic is being viewed.

xkcd: A webcomic of romance, sarcasm, math, and language.

See also: explain xkcd:Tagline

It's a kind of general mission statement for the xkcd comics. Nowhere is there a mention of humor, though it doesn't exclude it. In fact, there are some true downers.

In the early days (until April 2006) the tagline read as:

A webcomic of romance and geek humor. Updated on time every M/W/F since 1779.

(Old versions of the site can be viewed here.)