This is the template to use if you want your table of contents to be displayed at a particular location on the left side of your article, and yet have the article's text being displayed aside it. If you don't use it, and instead use __TOC__, then the table of contents will also be displayed where you choose, but the article's first section header will begin underneath it, leaving a tremendous amount of white space to the right of the table of contents. To use this, copy the following into your article:

{{tocleft}}