CSS glossary entries for ‘U’

Universal selector, (<code>*</code>): An arbitrary CSS selector, often called the wild-card selector. It matches the name of any element type. It is never used alone, because the absence of context prevents it distinguishing (i.e. selecting) between target elements and non-target elements. It is typically used in some sort of relationship selector to select a complete set of elements in a given context e.g. descendant selectors, child selectors, adjacent selectors, etc. Its indiscriminate nature makes it dangerous, but it can prove useful when browsers lack support for more precise selectors.
Unvisited hyperlink selector: See ‘unvisited link selector’.
Unvisited link selector: The unvisited link selector (E:link) is a CSS2 ‘pseudo-class selector’ which matches any link element whose target URL has not been saved in the user's browser history. In most cases, this selector should be used to set default link styles, since a rule which uses it can be overridden by the ‘visited link selector’, the ‘active link selector’ and the ‘focused link selector’. Whereas a rule with a simple a ‘element type selector’ cannot.