It’s a bit. It’s quite popular to link an xkcd whenever it’s relevant, along with one of a few different catch phrases. “Mandatory” being one of those. For this phrase in particular, the joke is that there is usually an xkcd for most situations, and that it is our “duty” as nerds to link to the appropriate one. It’s an inside joke for nerds. I hope this explains the custom to you.
Why is this mandatory? Who made the mandate?
It’s a bit. It’s quite popular to link an xkcd whenever it’s relevant, along with one of a few different catch phrases. “Mandatory” being one of those. For this phrase in particular, the joke is that there is usually an xkcd for most situations, and that it is our “duty” as nerds to link to the appropriate one. It’s an inside joke for nerds. I hope this explains the custom to you.
> It’s an inside joke for nerds.
I love inside jokes. I hope to be a part of one someday.
Bobby tables has a gun on my back
> Who made the mandate?
I did
It gets to the point where you don't have to click the link. You just think "Oh, #327 again."
Maybe xkcd needs its own url scheme, something like: xkcd://327
Edit: Written 8 years ago: https://github.com/biappi/XKCDUrlScheme
https://www.tau.ac.il/education/muse/maslool/boidem/97toldwr...
A lot of hassle to save two characters compared to a simple xkcd.com/327 :P
yeah, but _lots_ of style points!