De facto flag of Košice. This flag seems to be favored by the city, along with a flag appearing the same without a coat of arms, despite it having no swallowtail and not matching the patterns of Slovakian municipal flags, and already having a flag granted by the Slovakian Heraldic Registry.
Shield author information: https://ives.minv.sk/heraldreg/wp_detail.aspx?ID=3250
SVG shield: https://commons.wikimedia.org/wiki/File:Great_Coat_of_Arms_of_Ko%C5%A1ice.svg
Flag is visible all over the city, and in images such as [1].
Shield by unknown author, Jozef Králik, and Ladislav Čisárik; author of the greater version of the coat of arms and base of the flag unknown