Example of custom attribute definition

The following is an example of a custom attribute specialized from the existing base attribute.

<?xml version="1.0" encoding="UTF-8"?>

<!-- ============================================================= -->
<!--                    HEADER                                     -->
<!-- ============================================================= -->
<!--  MODULE:    Company Attributes Domain                         -->
<!--  VERSION:   1.0                                               -->
<!--  DATE:      October 2014                                      -->
<!--                                                               -->
<!-- ============================================================= -->

<!-- ============================================================= -->
<!--                    PUBLIC DOCUMENT TYPE DEFINITION            -->
<!--                    TYPICAL INVOCATION                         -->
<!--                                                               -->
<!--  Refer to this file by the following public identifier or an 
      appropriate system identifier 
PUBLIC "-//COMPANY//ENTITIES DITA Company Attribute Domain//EN"
      Delivered as file "companyAttDomain.ent"                     -->
<!-- ============================================================= -->

<!-- ============================================================= -->
<!--                    ELEMENT EXTENSION ENTITY DECLARATIONS      -->
<!-- ============================================================= -->

<!ENTITY % color-d-attribute
"color
(blue | brown | cyan | dkgray | gold | green | lime | ltgray | magenta |
mdgray | orange | purple | red | white | yellow)
#IMPLIED
"
>

<!-- ============================================================= -->
<!--                    DOMAIN ENTITY DECLARATION                  -->
<!-- ============================================================= -->

<!ENTITY color-d-att
"a(base color)"
>