Searching in the content of Documents is limited to Documents that have one of a limited set of file-extensions. This limit prevents the ITP/MDK Repository from returning bogus results when searching in Documents that contain binary data such as pictures and fonts.
If you do have Documents that contain valid data and that you want to have part in searching in content, but that has another extension than .doc, .docx, .odt, .txt, .ini, .cfg, .html, .htm, or .xml, you can specify the list of file-extensions included in content-search in the itprep.ini file of the ITP/MDK Repository server:
[Configuration]
ContentSearchFileTypes=doc;docx;odt;txt;cfg;ini;xml;html;htm
The setting lists the extensions that are included in full-text search in a semi-colon separated list. The value shown is the default value. You can add your own extensions.