Working Directly with Report Definition Language
When you write a report in Report Designer, the report is saved as an XML file with the Report Definition Language (RDL) extension .rdl. You can edit this file in Report Designer, a text editor, or any tool in which you can edit XML. In Report Designer, you can access RDL by viewing the code for the report.
Note
Editing RDL directly can result in a report that cannot be published to the report server or cannot run. As with any XML file, ensure that XML-specific characters used within elements are properly encoded.
Editing RDL
To view instructions about accessing RDL, see How to: View the Report Definition Language Source (Report Designer).
Report Designer creates RDL files according to the Report Definition Language XML Schema. When you publish the report, the report server uses the schema to validate the XML contained within the RDL file.
If you wish to include elements that are not part of the RDL schema, you can place them within the Custom element. Elements within the Custom element can be read by custom rendering extensions, but are ignored by the rendering extensions provided with Reporting Services. For example, you can use the Custom element to store comments within the report.