I try to describe here what the user (= owner–operator) of a personal computer needs to understand in order to gain the benefits provided by a capability design via a particular hypothetical GUI. I try to avoid jargon. This reveals concepts that the user needs whether he gains them by reading, or osmosis. This addresses design issues similar to these architectural notes. Earlier thoughts on this subject.

When you click on a guest icon in a web page you are inviting an agent to come to your computer and reside therein. The guest will be at your mercy, however, for you set the terms for his transactions with others. You are the landlord and the guest is a tenant. A guest has no lease unless you negotiate that by other means. The menu item guests shows you the list of current guests. Clicking on one brings up your control point for that guest. Here are the elements of a control point (red elements are directly adjustable here):