wpa_supplicant man page missing description of -C ctrl

From: Steven Friedrich <freebsdlouisville_at_gmail.com>
Date: Sun, 16 Jun 2024 03:59:24 UTC
wpa_supplicant – WPA/802.11i Supplicant for wireless network devices

SYNOPSIS
      wpa_supplicant [-BdhKLqstuvW] [-b br_ifname] -c config-file [-C ctrl]

What is the -C parameter?