Property:Corresponds to
"Corresponds to" is a declarative predefined property to define conversion factor for some unit of a physical quantity and is provided by Semantic MediaWiki. This property is pre-deployed (also known as special property) and comes with additional administrative privileges but can be used just like any other user-defined property.
corresponds to is a special property in Semantic MediaWiki with a built-in meaning: it gives the conversion factor for some unit of a physical quantity and the possible names for that unit. See Help:Custom units for the details.
For example, see on ontoworld.org how ow:Type:Time defaults to seconds but permits many other measurements of duration such as days, minutes, and hours, each with different abbreviations.