Super Mario Tricks? Or glitches?

[Travisto]

I recently bought an old Super Mario World strategy guide, because I am a collector, and It says there are "Tricks" where you can hold two items at once (Like a Key or turtle shell) and aswell hold items ontop of Yoshi, but this is my question... Are these real tricks? or are they glitches? http://www.kitsuneparadise.com/travisto/Keyoddities.jpg
Thats a link to a scan of the "Hold items on yoshi" thing.

[Chupperson Weird]

They could be either. Ptobably they were things they overlooked while testing the game and later thought they would be cool things to make people think were intentional.

"Don’t look into car headlights and freeze, because you might get run over or shot."