The file qurltlds_p.h is generated from the Public Suffix List (see [1] and [2]), by the program residing at qtbase/src/3rdparty/libpsl/src/psl-make-dafsa in the Qt source tree. To regenerate the file, run the following command from qtbase tree: src/3rdparty/libpsl/src/psl-make-dafsa public_suffix_list.dat src/network/kernel/qurltlds_p.h src/3rdparty/libpsl/src/psl-make-dafsa --output-format=binary public_suffix_list.dat \ tests/auto/network/access/qnetworkcookiejar/testdata/publicsuffix/public_suffix_list.dafsa Those arrays in qurltlds_p.h are derived from the Public Suffix List ([2]), which was originally provided by Jo Hermans . ---- [1] list: https://publicsuffix.org/list/public_suffix_list.dat [2] homepage: https://publicsuffix.org/