How does McMyAdmin handle whitelists?

How does popular Minecraft server admin tool McMyAdmin handle whitelists?

The Preferences tab lists the following options for Whitelist Mode: No whitelisting, Match any group, and Lockdown. And does it use whitelist.txt to set these options?


No whitelisting = Self explainatory

Match any group = Allow anyone who is assigned to a group to join

Lockdown = Allow anyone who is currently playing to continue playing but prevent any new connections.