Create a Ditaval file
You use the Ditaval view to create conditional processing profiles for your documents. Each profile that you create is stored in a .ditaval file.
A Ditaval file is created by specifying the conditions to exclude and to include when generating the output for a document. By default in the DITA open toolkit (DITA-OT), if a condition is not specified in the Ditaval file, then it is automatically included in the generated output. To exclude a condition, you must explicitly configure it as such in the Ditaval file. Any condition that is not explicitly excluded is included in the output.
When you create a Ditaval file in the Ditaval view, you can define the Default action as include, exclude, passthrough, or flag. For example, if you set the Default action to "exclude", then you would only need to specify the ones that you want to include.
To create a Ditaval file: