Hi, Looking in the ::gentoo repo I noticed there are 3 different /usr/bin/nc options available, net-analyzer/netcat, net-analyzer/openbsd-netcat and net-analyzer/nmap[symlink].
And packages that depend on net-analyzer/netcat must also explicitly list all of the available options where net-analyzer/munin, net-analyzer/netdata and xfce-extra/xfce4-sensors-plugin all missed net-analyzer/nmap[symlink] while app-forensics/air only lists net-analyzer/netcat. Additionally there could be even more options available in overlays, for example libressl provides an optional TLS-enabled nc(1) binary.