The s identifier in a CSS attribute selector matches attribute values case-sensitively in document languages like HTML where attribute values are case-insensitive.

The WebDriver protocol allows out-of-process programs to inspect and control browsers to, for example, run tests of web applications. Also known as WebDriver classic.

The touched property of a GamepadButton object indicates whether a button capable of detecting touch is currently touched.

The ::selection CSS pseudo-element selects text a user has highlighted.

The navigator.connection API provides information about the network connection a device is using and fires events when the connection type changes.

The ping attribute for <a> elements sets a URL to send a POST request to when the <a> is clicked. This is typically used for outbound link reporting.

The PaymentRequest API prompts the user to make a payment through the browser's user interface.

The speak-as CSS property sets how any element's content is spoken. Not to be confused with the speak-as descriptor of @counter-style at-rules.

The <input type="month"> HTML element shows a month picker.

TLS 1.3 sessions may be resumed more quickly by sending so-called early data to servers before the TLS handshake has finished. Also known as zero round-trip time resumption or 0-RTT.

The hand and pose properties of a Gamepad object represent the position in space and the hand that WebVR controllers are held in.

The lr, lr-tb, rl, rl-tb, tb, and tb-rl keyword values for the writing-mode CSS property set the text direction for elements in SVG 1.1 documents.

Touch events touchstart, touchmove, touchend, and touchcancel fire when users interact with a touch-sensitive surface, such as a screen or drawing tablet. These events are similar to mouse events.

The DOM level 2 style specification defined interfaces to access and modify CSS styles, such as CSSValue and CSSPrimitiveValue, that were later excluded from the CSS object model.

The cross-fade() CSS function generates an image by mixing two images.

The with JavaScript statement adds a given object to the chain of scopes used to evaluate names.

The inverted-colors CSS media query sets styles based on whether the user has inverted all colors, such as with mobile accessibility settings.

The Notification() constructor shows a message to the user, typically using the notification system of the host operating system.

The filter() CSS function applies one or more graphic effects to a CSS image, such as a background image. You can use functions, such as blur() and drop-shadow(), alone or combined to produce different effects. For instance, background: filter(url(image.png), blur(2px)).

The MediaSource API is a custom data source for media elements commonly used for adaptive streaming. Also known as Media Source Extensions (MSE).

The rel="prefetch" attribute for the <link> HTML element is a hint to the browser that the user is likely to navigate to a resource, so the browser should preemptively fetch and cache the resource.

The __defineGetter__() and __defineSetter__() methods of objects bind a function to a property, which is called on setting or reading the property.

The setPosition() and setOrientation() methods of the AudioListener API set the virtual position and orientation of a person relative to sound sources, to spatialize audio in a Web Audio context.

The device-aspect-ratio, device-height, and device-width media features describe physical properties of the displaying output device.

The caller and arguments properties of a non-strict mode Function object are the function that called it and the arguments it was called with. Not to be confused with the arguments variable in a function body's local scope.

JavaScript built-in methods such as, String.bold() and String.italics(), wrap strings in (often historic) HTML.

The page-break-before, page-break-inside, and page-break-after CSS properties are aliases to the break-before, break-inside, and break-after properties.

The :first, :left, and :right pseudo-classes select pages based on their position in sequence after pagination.

The compile() method of RegExp objects recompiles an existing regular expression object using a new pattern and flags.

The RegExp object has several static properties to access the input and results of the most-recent regular expression match.