Nomenclature and description of Electro-Luminescence (EL) observations: cell cracks and other observations Bengt Jaeckel, Matthias Pander, Paul Schenk, Aswin Linsenmeyer and Jochen Kirch EPJ Photovolt., 15 (2024) 44 Published online: 23 December 2024 DOI: 10.1051/epjpv/2024039