2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/143630This addendum adds some comments to a published paper (B. Schroer, Class. Quantum Grav. 23, (2006) 5227) on area density of localization-entropy. The setting of holography and localization-entropy is generalized to double cones and black holes with bifurcate Killing horizons. PACS: 11.10.-z, 11.25.Hf, 04.70.Dy14 pages latex, gain of clarity through improvements of formulationsHigh Energy Physics - Theorytext