Only relevant thing I could find in reference to "Threshold Identification"
https://ieeexplore.ieee.org/document/202193
It appears to be a military security term.
"In many applications, one needs to identify a user's organization rather than his individual identity.
A threshold identification scheme is a scheme in which the proof of the group identity can be identified if the members in the group who agree to prove their group identity anonymously is larger than t/sub g/(>"
I think this is a major habbening boys.