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Eh hem some of that stuff most people know, and the possible names stink. However look at the picture!!!!!
Yes it says it came from Johto I think its good proof and the fact that in D/P they mention G/S like 100 times. So just thought this info would good to point out.
-Missingno. The Glitch Hunter

I tried getting Pokemon from Jhoto. Using the AR I no longer use for anything (but SM64DS :P) I was able to successfully obtain 3 Unown and a Slowpoke from "Jhoto", 2 Unown in Great Balls and the other Unown and Slowpoke in Net Balls. (Unown in Net Ball?) What? Well, I did catch Rayquaza with a Dive Ball in Emerald?

*topic*

Yeah, but I released them along with everything else in my box (Lv. 86 Myuu!!!Yes, I said Myuu not Mew because it was Japanese) so I don't have them, and I forgot how to get them again. Great... Now I don't have proff! Oh well...

thats not really the point you're the third source I've heard it from so this looks good!
Would game freak put in something you can't get besides glitches?

Eh. Could just be there as an Easter egg or something. You know, a bonus to whoever finds it. Or it could be there in case they decide to make a G/S remake - it's possible that they don't know. Or it's possible that they're planning one...I really don't know. Just...don't get your hopes up.

I don't think so remember the last time they put all those little hidden things refrencing the old games they made FR/LG
plus come on so many people would pay to buy the game and you know how major companies love to make money