What is the -l (lowercase L) switch of the ssh-agent command?

I see the following on macOS:

$ ps ax | ag ssh-agent
8677   ??  S      0:00.60 /usr/bin/ssh-agent -l

Looked up ssh-agent's man page on the terminal, but it has no mention of a -l switch. None of the online man pages I found so far (neither this nor this) mentions it.

This seems to a macOS-specific feature, but couldn't find it documented anywhere (yet):

$ /usr/bin/ssh-agent -l
launch_activate_socket(): No such process

$ which ssh-agent
/nix/store/kgp4br70j8w4k4lgsv8sk22hb51km36s-openssh-9.1p1/bin/ssh-agent                                                                                                                                                                                                       

$ ssh-agent -l
ssh-agent: illegal option -- l

Based on the google results of /usr/bin/ssh-agent -l error message, -l probably stands for "listener"?