Integrate the emphasisDomain specialization

Inspired by Eliot Kimber's tutorials at http://dita4practitioners.github.io/dita-specialization-tutorials/, let's assume you have created a domain specialization, Emphasis, that includes a new element, <em> to be used to mark text for emphasis. This specialization includes the two files emphasisDomain.mod and emphasisDomain.ent. (Examples of both of these files are included as appendices.) The specialization does not include a DTD file because it is a domain specialization. A domain specialization never includes a DTD because it cannot be used on its own, contrary to a topic type specialization.

Add emphasisDomain.mod and emphasisDomain.ent to the dtd subfolder of your DTD plugin.
Check out and open CompanyDitabase.dtd.

In the DOMAIN ENTITY DECLARATIONS section, add the following:

<!ENTITY % emphasis-d-dec
  PUBLIC "-//COMPANY//ENTITIES Emphasis Domain//EN"     
         "emphasisDomain.ent"                                                
>
%emphasis-d-dec;

In the DOMAIN EXTENSIONS section, edit the keyword entity to include emphasis-d-keyword:

<!ENTITY % keyword      "keyword |
                         %pr-d-keyword; | 
                         %sw-d-keyword; |
                         %ui-d-keyword; |
                         %emphasis-d-keyword;
                        ">

In the DOMAINS ATTRIBUTE OVERRIDE section, edit the included-domains entity to reference &emphasis-d-att:

<!ENTITY included-domains 
                          "&concept-att;
                           &glossentry-att;
                           &glossgroup-att;
                           &reference-att;
                           &task-att;
                           &hi-d-att;
                           &ut-d-att; 
                           &indexing-d-att;
                           &hazard-d-att;
                           &abbrev-d-att;
                           &pr-d-att; 
                           &sw-d-att;
                           &ui-d-att; 
                           &taskbody-constraints; 
                           &localization-loc-d-att;
                           &emphasis-d-att;
  "
>

In the DOMAIN ELEMENT INTEGRATION section, add the following:

<!ENTITY % emphasis-d-def  
  PUBLIC "-//COMPANY//ELEMENTS Emphasis Domain//EN"   
         "emphasisDomain.mod"
>
%emphasis-d-def;

Save, close, and check in CompanyDitabase.dtd.
Check out and open your DTD plugin's catalog.xml.

Within the group that includes CompanyDitabase.dtd, add the public identifiers for the emphasisDomain.mod and emphasisDomain.ent files.

<group>
   <!-- Topics -->
   <public publicId="-//COMPANY//DTD DITA Composite//EN" uri="dtd/CompanyDitabase.dtd"/>
			
   ...

   <!-- Company Emphasis domain --> 
   <public publicId="-//COMPANY//ELEMENTS Emphasis Domain//EN" uri="dtd/emphasisDomain.mod"/>
   <public publicId="-//COMPANY//ENTITIES Emphasis Domain//EN" uri="dtd/emphasisDomain.ent"/>
</group>

Save, close, and check in catalog.xml
Restart the IXIASOFT CCMS Desktop.
To add the specialization to IXIASOFT CCMS Output Generator, do the following:
1. Copy the entire com.company.dtd plugin folder into the %OutputGenDir%/data/%OT_Dir%/plugins folder, overwriting the existing copy.
  
  Depending on your CCMS Output Generator configuration, the DITA-OT path might vary.
2. Run the integrator to integrate the plugin.

You can now add the <em> element to your content, in any context where you could add <keyword>.

You also need to add templates and CSS or attribute sets to your output plugins to properly format text in the <em> element.