Man pages matching name zmq::ffi::constants in section 3pm:

ZMQ::FFI::Constants.3pm.en	debian 10 / libzmq-ffi-perl
ZMQ::FFI::Constants.3pm.en	debian 11 / libzmq-ffi-perl
ZMQ::FFI::Constants.3pm.en	debian 12 / libzmq-ffi-perl