Reply Code 0x8083 vs 0x8080

[Jiann-Ming Su]

What could cause BIND to respond with reply code 0x8083 (no such name) vs 0x8080 (no error)?

I have an app doing srv queries without the domain name appended.  One time, server will respond with no such name (flags 0x8083) which causes the app to query again with domain name appended.  Another time, the DNS server responds with no error (flags 0x8080) which causes the app to query again without the domain suffix appended.

I may very well be debugging an application problem, but I'm curious as to why BIND would respond with different codes.  Thanks for any insights.