By default, the Document toolbar contains tools for manipulating document content. Tools commonly found on this toolbar are described below. For a complete list of tools that can be placed on a toolbar and more information about customizing them, see Tools and Toolbars.
If the toolbar is currently hidden, go to Tools > Toolbars and select it to show it.
Headers and Footers: Click the main button to open the Header and Footer dialog box, from which you can add a new header and/or footer (if none currently exist on the page) or edit the current header and/or footer. Click the arrow to the right to invoke the Headers & Footers menu.
Add: Adds a new header and/or footer to the document.
Edit: Edits the document's existing header and/or footer.
Crop Pages (SHIFT+ALT+O): Crops the page to remove unwanted content.
Flatten (CTRL+SHIFT+M): Flattens markups in the current document, moving them from the markup stream into the main body of the PDF, rendering them uneditable.
Erase Content: Removes text, vectors, and images from documents.