6.1.3.5 Extensibility: The DNS defines domain name syntax very generally -- a string of labels each containing up to 63 8-bit octets, separated by

6.1.3.5 Extensibility: The DNS defines domain name syntax very generally -- a string of labels each containing up to 63 8-bit octets, separated by dots, and with a maximum total of 255 octets. RFC1035 makes this more explicit [1]. [1] https://www.freesoft.org/CIE/RFC/1035/9.htm https://www.freesoft.org/CIE/RFC/1035/9.htm