Kashing

I did research alot but still feelling confuse. Here's some examples. Breed Survey Class: 1 <- 1=good? HD Classification: 'A' (1:2) <- what is 1:2? Elbow Classification: 'Z' (0:0) <- the same Can someone explain for this? XXXX Millie Moon (Millie) BSCL 1 VG A 1:3 Z 0:0 (XXXX is breeder's name so not display.) to Zony v. Haus Gerstenberg Kkl. I Sch HIII a N. Ed N. (Imp Gmy) ZW77 I am going to purchase a puppy from those parents. Do they healthy and reliable?