The Horizontal Rule button to the right of the Table button will let you add a horizontal rule. Please note that these can be difficult to remove if you later change your mind about them. The easiest approach for removal is to make a copy of the text directly above and below the horizontal rule, then select that text and the rule and delete. You can then paste only the text back into your page.

The Special Character drop-down [] lets you insert special characters, including letters with diacritics

The Choose Language drop-down lets you mark a passage of foreign text with the language name of the text. This helps screen readers to know how to read and pronounce the text. Only a few languages are supported, but if posting a passage in one of those languages, it should be marked accordingly for accessibility support.