The left margin in Fargo contains a column of icons for frequently used actions.
The + icon adds a new item to a calendar-structured sub-outline in the current outline. It creates headlines as it needs to. The top-level headline of the calendar is the current year. Under that is the month, and below that is an entry for each day. When you click the + it creates a new item under the current day, ready for you to type into it. Try it and you'll immediately see what it does.
The B, I and
S icons bolden, italicize and strikethrough the selected text. If you're in structure mode, it does this to all the text in the bar cursor headline.
The link icon creates an HTML link if you're in text mode, or if you're in structure mode, it turns the headline into a link node.
The suitcase icon is a direct link to the Edit Attributes dialog.
The share icon renders just the document pointed to by the bar cursor, none of its parents or sub-documents. It's useful when you have configured Fargo, via the Outline Settings dialog, to not automatically render after every change, or if you just want one page rendered, and not all of its subs and parents.
The home icon, if present, allows you to visit the home page of the website the bar cursor headline is inside of.
The eye icon, if present, allows you to view the contents of the bar cursor headline on the web. For example if it's pointing to a link node, you'll visit the page the link node points to.