Directly copied from Ironcross's explaination:

This plugin is for MUSHclient and allows you to set up two containers or the ground and do transfers easily. It works best if you're going to be using
the same set of containers, or their reverse. It works like this:
1. type fromcont, a space, and then a container name. Do the same for tocont.
2. You can then make transfers by typing qt, a space, and then the name of an item found in whatever fromcont is.
Ex: fromcont backpack; tocont ground; qt poultice; qt 3 bandage.
3. If you need to reverse them, this can be done simply by typing swapconts.

The plugin will tell you what you've set each to, and tell you the order when you use swapconts, so you're never left wondering if it worked or not. It
should also remember how you left it when you restart the client, provided you saved the session.

Huge credit goes to Ironcross32, the maker of this awesome plugin.