::placeholder. The ::placeholder pseudo element (or a pseudo class, in some cases, depending on the browser implementation) allows you to style the placeholder text of a form element. As in, the text set with the placeholder attribute: <input type=email placeholder=jane@firefly.com>.
Australian Capital Territories. As of 1996 A.C.T. changed it's name to ACT. It no longer stands for American College Testing since they do so many other things besides just the testing.
Created by ACT Inc., the ACT is an entrance exam used by most colleges and universities to make admissions decisions. The idea (in theory, at least) is to provide colleges with one common criterion that can be used to compare all applicants. The weight placed on ACT scores varies from school to school.