My e-mail sig for certain ham radio related lists says "sent from my J-38". For those not in to radio, the J-38 was a very common telegraph key, widely used by the US military in WWII, and by many radio amateurs after the War. It's a joke, son.
One correspondent made the observation that a "sent from my ..." line in the signature often really means the following: If you send more than a one line reply, I probably won't bother scrolling through it and reading it on my device. Don't bother embedding any images in your reply, because I probably won't download them, or if I do, I'll see them on such a tiny screen that I won't be able to resolve anything. And don't send me on a link to a website that requires more than 150x300 resolution.
sent from my J-38 using Morse, the ORIGINAL tapatalk.