The Scattered Name Service Disgregation (SNSD) is the ANDNA equivalent of the SRV Record of the Internet Domain Name System, which is defined by RFC 2782.
SNSD isn't the same as the "SRV Record", it has its own unique features.
With SNSD it is possible to associate IP addresses and hostnames to another hostname. Each assigned record has a service number, in this way the IP addresses and hostnames which have the same service number are grouped in an array. In the resolution request the client will specify the service number too, therefore it will get the record of the specified service number which is associated to the hostname.