DTD Entities

Entities are used to define shortcuts to special characters.Entities can be declared internal or external

An Internal Entity Declaration

Syntax

<!ENTITY entity-name "entity-value">

Example

DTD Example:

<!ENTITY writer "Donald Duck.">
<!ENTITY copyright "Copyright w3resource.">

XML example:

<author>&writer;&copyright;</author>
Note: An entity has three parts: an ampersand (&), an entity name, and a semicolon (;).

An External Entity Declaration

Syntax

<!ENTITY entity-name SYSTEM "URI/URL">

Example

DTD Example:

<!ENTITY writer SYSTEM "/entities.dtd">
<!ENTITY copyright SYSTEM "/entities.dtd">

XML example:

<author>&writer;&copyright;</author>