Lately the system requests for me to enter /QUOTE PASS 13485 in order to logon on mIRC.
What is the function of this text and why is it popping up recently?
Any risk?
No risk, some servers require a password to be able to login.
Either you're connecting to a server that requires a password or you're connecting through a bouncer (BNC) which requires a password, in either case it's not an mIRC issue.
A number of servers/networks now ask that unident'd users type a command to prove that they're human. If you enable the identd server in mIRC (/identd on [color:green]kingme[/color]) and allow mIRC/port 113 through your firewall/router then you should stop receiving that message.