The ValidityState interface represents the validity states that an element can be in, with respect to constraint validation. Together, they help explain why an element's value fails to validate, if it's not valid.
The read-only property ValidityState.badInput indicates if the user has provided input that the browser is unable to convert. For example, if you have a mail input element whose content does not have a '@'.
The Window.self read-only property returns the window itself, as a WindowProxy. It can be used with dot notation on a window object (that is, window.self) or standalone (self). The advantage of the standalone notation is that a similar notation exists for non-window contexts, such as in Web Workers. By using self, you can refer to the global scope in a way that will work not only in a window context (self will resolve to window.self) but also in a worker context (self will then resolve to WorkerGlobalScope.self).
WindowTimers is a mixin used to provide utility methods which set and clear timers. No objects of this type exist; instead, its methods are available on Window for the standard browsing scope, or on WorkerGlobalScope for workers.
The WorkerNavigator interface represents a subset of the Navigator interface allowed to be accessed from a Worker. Such an object is initialized for each worker and is available via the WorkerGlobalScope.navigator property obtained by calling window.self.navigator.
The HTML <nobr> element prevents a text from breaking into a new line automatically, so it is displayed on one long line and scrolling might be necessary. This tag is not standard HTML and should not be used. Instead use the CSS property white-space like this:
The HTML Plaintext Element (<plaintext>) renders everything following the start tag as raw text, without interpreting any HTML. There is no closing tag, since everything after it is considered raw text.