Man pages matching name visir_util_spc_txt2fits in section 7:

visir_util_spc_txt2fits.7.en	debian 10 / cpl-plugin-visir-doc
visir_util_spc_txt2fits.7.en	debian 11 / cpl-plugin-visir-doc
visir_util_spc_txt2fits.7.en	debian 12 / cpl-plugin-visir-doc