[mikewarot]

I never noticed the disclaimer at the bottom until today

  xkcd.com is best viewed with Netscape Navigator 4.0 or below on a Pentium 3±1 emulated in Javascript on an Apple IIGS
  at a screen resolution of 1024x1. Please enable your ad blockers, disable high-heat drying, and remove your device
  from Airplane Mode and set it to Boat Mode. For security reasons, please leave caps lock on while browsing.

Also, the font chosen is all caps

[Lutzb]

I would not be surprised if an easter egg exists on xkcd.com provided you satisfy these requirements.

[wltr]

Aha, especially the boat mode.

[Lutzb]

Maybe something like

> Mozilla/4.0 [en] (AppleIIGS; U; P3±1-emu; 1024x1; BoatMode; CapsLk)

[ButlerianJihad]

https://www.explainxkcd.com/wiki/index.php/Footnote