The registry requires a permanent marking for registration, and on-line registration or paper forms give you a space to indicate the herd# and whether you placed it in the left ear, right ear, or both ears. I believe many use the year check digit, with 2014 being the letter "B", but this is not a requirement and some use a numbers-only method. A common thing to do is use the letter check digit indicating year followed or preceded by what number in line the calf was born that year. Some add the year digit to an elite donor's number, so donor 503 would have calf "4503" born this year. The registry is pretty flexible. We use green paste and they show up really nice. The vet will add a green tattoo in the right ear mid rib area for the Brucellosis vaccine in heifers, so leave that area open for the vet, if possible.
Cigar actually has a lengthy one, LHDE46 which covers it all...breeder, year of birth, and probably he was #46 born that year. Crews Farms precedes all their numbers with "CF"
Use what works for you.