Interferometric Coherence Across Scales: Phase and Temporal Signatures in Gravitational Wave, Radio, and Optical Interferometry

We classify interferometric observables from three domains — gravitational wave (LIGO/Virgo/KAGRA), very long baseline radio (EHT/ALMA/VLBA), and optical/infrared (VLTI/GRAVITY) — within the taxonomic framework of Paper XXII. For each domain we explicitly separate physical coherence (Classes I–III) from instrumental coherence, identify existing diagnostics already routinely measured, and map them to specific proxy observables. This paper is classificatory; it does not derive RCD predictions for interferometric data nor propose new experiments.