In CSS, canonical order is used to refer to the order in which separate values need to be specified (or ) or are to be as part of a CSS property value. It is defined by the formal of the property and normally refers to the order in which longhand values should be specified as part of a single shorthand value.

For example, shorthand property values are made up of several background-* longhand properties. The canonical order of those longhand values is defined as

Furthermore, its syntax defines, that if a value for the is given, it must be specified after the value for the , separated by a slash. Other values may appear in any order.

See also

• CSS value definition syntax

• What does “canonical order” mean with respect to CSS properties? on Stack Overflow provides useful further discussion.