Can I use a motorcycle tire made for the front on the rear of my bike?

I‘m trying to find white wall tires for my motorcycle. My bike is a ‘78 Suzuki Gs750. My problem is that no one makes a white wall that fits an 18‘ rear rim. But I can find a front tire that will fit. My question is what designates front from rear, and will it hurt to use a front tire on the rear?ps. the tire i‘m thinking of using is 120/90h18 Dunlop K177