The imaginary part of each zero is recorded with an absolute precision of and the completeness of the list was checked using a rigorous version of Turing's method; see [MR:3315519, 10.1090/S0025-5718-2014-02884-6] for further details.
The results have been checked to a separate list of zeros independently computed by Jan Büthe to an accuracy of (this comparison found 108 minor discrepancies, each of which was resolved in favor of the data presented here).