WebKit CSS extensions - CSS: Cascading Style Sheets
ring -webkit-svg-shadow t -webkit-tap-highlight-color -webkit-text-combine -webkit-text-decoration-skip -webkit-text-decorations-in-effect -webkit-text-fill-color -webkit-text-security -webkit-text-stroke-color -webkit-text-stroke-width -webkit-text-stroke -webkit-text-zoom -webkit-transform-origin-x -webkit-transform-origin-y -webkit-transform-origin-z u -webkit-user-drag -webkit-user-modify * a few are on the standards, unprefixed track ** new syntax has been standardized.

user-modify - CSS: Cascading Style Sheets
examples html <div class="readwrite">the user is able to change this text.</div> css .readwrite { -moz-user-modify: read-write; -webkit-user-modify: read-write; } specifications not part of any standard.