[Tails-dev] firefox -allow-remote (what does it do?)

when i do:

$ps ax | grep firefox

i see:

/usr/local/lib/tor-browser/firefox -allow-remote --class Tor Browser -profile /home/amnesia/.tor-browser/profile.default

what is the "-allow-remote" value mean? I've Googled
and eventually discovered this site:

github(com)/micahflee/torbrowser-launcher/issues/157#issuecomment-101051186

"In the TBB 4.5 they updated the star-tor-browser script,
which actually removed support for passing -allow-remote
in anyway. So I've removed support for opening external
links, which sort of makes this issue go away. #176"

if they removed support in TBB version 4.5 for this
option, why in Tails 1.7 does it remain and what exactly
does it do?

the few websites where it's mentioned do not do a good job
of explaining this, what i have come to understand now,
outdated/removed option.