Samuel Yates began, and this site continues, a database of the largest known primes. Primes in that database are assigned a proof-code to show who should be credited with the discovery as well as what programs and projects they used. (Discoverers have one prover-entry, but may have many proof-codes because they use a variety of programs...)
This page provides data on c81, one of those codes.
Code name (*): c81 Persons (*): 2 (counting humans only) Projects (*): 0 (counting projects only) Display (HTML): Water, Underwood, Primo Number of primes: total 1 Unverified Primes: 0 (prime table entries marked 'Composite','Untested', or 'InProcess' Score for Primes (*): total 35.9360, on current list 35.9360 Entrance Rank (*): mean 55139.00 (minimum 55139, maximum 55139)
Below is additional information about this entry.
Display (text): Water, Underwood, Primo Display (short): Water & Underwood Database id: 7990 (do not use this database id, it is subject to change) Proof program: Primo The primes from this code accounts for 0.257% of the (active) primes and 0.002% of the (active) score for this program. Entry last modified: 2021-10-21 18:38:07