You can create, delete and rename a section by clicking on the corresponding toolbar button. Similar buttons also exist for branches. If there are more than one sections (or branches) defined, then you can select from the drop-down controls the one you wish to be the ‘active’ section (or branch). By default the active branch is the ‘Main Branch’ and the active section is the ‘Main Section’. Every time you add a unit procedure, it is automatically added to the active section.