Pellon102R Fuse Vinyl, Clear

What does the "r" mean"? what's the difference between 100 fusible vinyl vs 100r fusible vinyl? or 102r in this case?

Is this machine washable when applied to canvas? I want to use it for a shopper tote bag.

After applied, does it lighten, make cloudy or change the appearance of the colors of the fabricin any way? Thanks.

I want to use this on a tote bag to make it stain resistant. Do you recommend adding this before or after sewing?