B. Definitions (pdf)

14.
A Closed Flock is one that:
   
a.
Never brings in new sheep of unknown or lower status regardless of subsequent testing.
   
b.
Only brings in semen and embryos that meet the biosecurity requirements.
   
c.
Only brings in sheep from other “A” status flocks.
   
d.
Does not have sheep that leave and return (e.g. from shows or displays) unless those sheep are housed in an Isolation Facility as defined above while away, and transported in a vehicle that meets the requirements listed in Section C. Protocols.