It is also possible to use (by default enabled in the YSFReflector.ini) a callsign check based on a regular expression to check the callsign plausibility in callsign-format and length.
The result of this check can be overdriven by a whitelist-entry in the blocklist (for example: N0CALL is blocked by default by this expression but could be allowed for special bridging situations).
There is also a functionality implemented that prohibits parallel transmissions that can happen if two senders transmit at the same time. Here the principle 'first-comes-first-serves' is realized, so the second station in time will just be muted to not disturb the audio.
In most installations this packages are already installed, otherwise you easily can install them with your system-package-manager (for example Debian: apt) or you use pip3 install <package>-command.
The configuration file (YSFReflector.ini) is based on the origin YSFReflector.ini of G4KLX's YSFReflector but with added new configuration-items. So If you know the old reflector-software - configuring this one would be straight forward.