/plot middle - Teleport to the middle of the plot you're in.
/plot trust - Allow a player to build in your plot.
/plot add - Add a player to your plot. Allows them to build while you're online.
/plot deny - Block a player from your plot.
/plot remove - Remove a player you've added from your plot.
/plot merge [all|north|east|south|west] [removeroads] - Merge plots together. Can only be used if you have multiple plots claimed next to each other. Use "/plot merge" to merge in the direction you're looking, specify "all" to merge all, or specify a specific direction to merge in. Specify "removeroads" to leave roads in-tact when merging.
/plot unlink - Unmerge plots that have been merged together. Will unmerge all plots in a "megaplot".
/plot flag - Set a flag for your plot. This lets you control things like the plot's weather, time, music, etc.
/plot desc - Add a description for your plot.
/plot alias - Add a name for your plot.
/plot sethome - Set the home location for your plot.
/plot toggle - Toggle plot chat or the titles that appear when you enter a plot.
/plot inbox - View the comments for your plot or delete them.
/plot comment - Comment on a plot.
/plot chat [message] - Send a message to plot chat or toggle plot chat on/off.
/plot save - Save your plot. Useful for restoring it if you mess something up.
/plot load - Load your saved plot.
/plot download - Download your plot as a .schematic file.
/plot set value - Set various aspects of your plot.
/plot clear - Clear your plot. This will remove everything in it.