2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/206695The holographic relation between local boundary conformal quantum field theories (BCFT) and their non-local boundary restrictions is reviewed, and non-vacuum BCFT's, whose existence was conjectured previously, are constructed.16 pages. Contribution to "Rigorous Quantum Field Theory", Symposium in honour of J. Bros, Paris, July 2004. Based on joint work math-ph/0405067 with R. LongoMathematical Physics81R15; 81T05; 81T40text