The comma thread portal is an attempt to present in a condensed form the entire scope of the EO forum threads on comma use (as of June 2013) in order to facilitate the search for information on this extensive subject. The threads have been divided into 19 main categories, most of them with subcategories. Each main category contains: (1) an info post (indicated by the smiley), which briefly explains pertinent concepts, (2) key word links that return lists with relevant thread titles, and (3) the topic sentences of the individual threads as well as their specific links. The index section below summarizes the content of this thread portal. Each index word should be understood as related to comma use. For example, the linked index item that refers to comma use with regard to the word that.