To create a new tab in the sidebar menu:

1. Create a tiddler and tag it with the SystemTag tag $:/tags/SideBar
   • To create a table of contents you can populate the new tab tiddler using the table-of-contents macros. For example, see the TableOfContents used here
2. By default, the tiddler title is used as the tab title but you can override it using the caption field
3. To define the tab ordering, use the list-after or list-before fields as discussed in Tagging
   • For example: set list-after to $:/core/ui/SideBar/Open to place a sidebar tab immediately after the "Open" tab

Note that you can create new tabs under the "More" tab in the same way by using the tag $:/tags/MoreSideBar.