The HTML <base> element specifies the base URL to use for all relative URLs contained within a document. There can be only one <base> element in a document. 
The HTML <head> element provides general information (metadata) about the document, including its title and links to its scripts and style sheets.
The HTML <style> element contains style information for a document, or part of a document. By default, the style instructions written inside that element are expected to be CSS.
The HTML <title> element defines the title of the document, shown in a browser's title bar or on the page's tab. It can only contain text, and any contained tags are ignored.
Returns the currently focused element, that is, the element that will get keystroke events if the user types any. This attribute is read only.
anchors returns a list of all of the anchors in the document.
The document.close() method finishes writing to a document, opened with document.open().
Get and set the cookies associated with the current document. For a general library see this simple cookie framework.
The Document.dir property is a DOMString representing the directionality of the text of the document, whether left to right (default) or right to left. Possible values are 'rtl', right to left, and 'ltr', left to right.
embeds returns a list of the embedded OBJECTS within the current document.
forms returns a collection (an HTMLCollection) of the <form> elements within the current document.
The Document.fullscreen read-only property reports whether or not the document is currently displaying content in fullscreen mode.
The Document.fullscreenElement read-only property returns the Element that is currently being presented in full-screen mode in this document, or null if full-screen mode is not currently in use.
The Document.fullscreenEnabled read-only property returns a Boolean that reports whether or not full-screen mode is available. Full screen mode is available only for a page that has no windowed plug-ins in any of its documents, and if all <iframe> elements which contain the document have their allowfullscreen attribute set.