An entity used to represent information within the context of a document type definition. Parameter entities may be used to link the content of additional DTD files to a DTD, or as an abbreviation for frequently repeated declarations. Parameter entities are distinguished from general entities by their use of a percent sign (%) rather than an parent element of the SECOND element.
An entity that consists of DTD specifications, as distinct from a general entity. A parameter entity defined in the DTD can then be referenced at other points, in order to prevent having to recode the definition at each location it is used.
An entity used exclusively within a DTD, never in a document.
An entity usually referenced in the DTD by a name that starts with a percent sign (%) and ends with a semicolon. In DocBook, parameter entities are mainly used to facilitate customization of the DTD, but they can also be used to control marked sections of a document.
an entity whose scope of use is within the document prolog (i.e., the external subset/DTD or internal subset). Parameter entities are disallowed within the document instance.
An entity type often used in the DTD or a document's internal subset. The entity's name starts with a percent sign (%) and ends with a semicolon.
A special entity type reserved for use in a document's DTD that is designed to hold lists of attributes and content models.
In SGML, parameter entities refer to the entities within a DTD or other document that will be occupied by whatever value for that entity is passed in as input when rendering or analyzing the document.
