Interpretation of Chat flag letters

[SlySven]

I've been running a comparison of MUD clients that implement the MMCP chat protocol (as part of adding it to Mudlet).

One oddity that caught my eye was a difference in the meaning of the 'F' character. According to the MudMaster documentation, 'F' means something about a Firewall (maybe the detected incoming connection is on a different IP address to the one it advertises) whereas 'T' is used to show that this client instance will accept file transfers from that peer:

However, I noted that MUSHClient uses 'F' to indicate file transfers will be accepted instead of the 'T' that MM uses - is this intentional or accidental?

BTW Is there a method to set the IP address that MUSHClient advertises when it tries to make a connection to another peer? I could not see a way to set this but it'll be needed if it is behind a ISP's NATing modem/router and a central server is not being used...