[Shrugging]

The "corner-peel-back" technique may put you in greater danger of "microwave boil-over" than the "slit" technique.

Personally, I'm a "corner-peel-back" acolyte (regardless of the printed instructions) mainly becuz I don't care to dirty a knife just to cut a slit in the film.

Yeah Auntie, I bring it up because I pretty much gave up on the dirtying-a-knife-for-no-reason routine myself. We're just microwaving mavericks, you'n me.

The main difference is that there is one less word in "Cut Slit in Overwrap" thereby saving the manufacturing company money on printing costs. :)