Any URI can be used for a literal datatype, but usually XML Schema (XSD) datatypes are re-used for typing literals.
    任何URI都可用于文字数据类型，但通常情况下，XML模式(XSD)数据类型会被重复用于文字类型。image.png

    In Turtle:
    image.png
    **
    Usually we will also define a prefix for the XML Schema types, conventionally “xsd” so that when we are typing, say, a date as above we can write: “2004-02-10”^^xsd:date