Extra Toolbar
The extra toolbar is not displayed by default. You can choose to display it from the View menu.
Inserts a hyperlink into your document. It opens the Insert Hyperlink dialog.
Inserts a bookmark (also known as an anchor from the HTML tag <a>, hence the icon) into your document. It opens the Insert Bookmark dialog.
Buttons that add lines to text
All of these buttons work similarly: when you select text and click on a button, the text is transformed. If you click on a button while no text is selected, the new state applies to any text you type.
Adds an overline to the text.
Strikes through the text.
Adds a top line to the text. A top line is further above the text than an overline, and is most useful when constructing tables.
Adds a bottom line to the text. A bottom line is further below than text than an underline, and is most useful when constructing tables.
Other buttons
Sets the text to superscript.
Sets the text to subscript.
Opens the Insert Symbol dialog.
Executes a perl script. It only functions if there are scripts available.
Sets the amount of space left before a new paragraph. The left button sets it to zero, the right to 12 points. Typographically, a 12-point gap between paragraphs is too much. If you want a gap between paragraphs, a more reasonable amount would be 4 points. You can set interparagraph spacing by modifying the style for the paragraph.
Sets the line spacing. The left button sets the lines to single spacing, so that there is little space between lines. The middle one sets one-and-a-half spacing, so that the space between lines is half the height of the lines. The right one sets double spacing, so that there is enough space between two lines of text to insert another line.
Moves the insertion point to the page header. If there is no header, clicking it creates one.
Moves the insertion point to the page footer. If there is no footer, clicking it creates one.
Removes the header from the document if one exists.
Removes the footer from the document if one exists.