A server SHALL assign a unique <Instance> label of up to 63 bytes in UTF-8 format for each DNS SRV/TXT record pair that it advertises. In order to avoid name conflicts, <Instance> names SHOULD begin with a meaningful substring followed by a hyphen (-) and end with the device’s SFDI or other collision-resistant substring, such as the low-order bits of an EUI-64 in text form (e.g., device- 000001111114). Should a name conflict occur, a device SHALL assign itself a new name until conflicts are resolved. A conflict SHOULD be resolved by appending a decimal integer in parentheses to the <Instance> (for example, Name(2) for the first conflict, Name(3) for the second conflict, etc.).
If a DNS SRV/TXT record pair is created to advertise a function set, its <Instance> SHOULD consist of the corresponding string from the Subtype column of Table 17 followed by a hyphen and a collision- resistant substring as defined above (e.g., upt-000001111114). When an SFDI is used as part of a DNS-SD
label, it SHALL be represented as 12 decimal digits including leading zeros (if any) as well as the checksum digit, and SHALL NOT include embedded hyphens.