System identifier

From Wikipedia, the free encyclopedia
Jump to: navigation, search

A system identifier is a document processing construct introduced in the HyTime markup language as a supplement to SGML. It was subsequently incorporated into the HTML and XML markup languages.

In HyTime, there are two kinds of system identifier: formal system identifier (FSI) and simple system identifier.

In HTML and XML, a system identifier is a fragmentless URI reference. It typically occurs in a Document Type Declaration. In this context, it is intended to identify a document type which is used exclusively in one application, whereas a public identifier is meant to identify a document type that may span more than one application.

In the following example, the system identifier is the text contained within quotes: