/usr/bin/urxvtcd is in rxvt-unicode 9.19-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7
#!/bin/sh urxvtc "$@" if [ $? -eq 2 ]; then urxvtd -q -f exec urxvtc "$@" fi