To many of us, submitting a disavow link file to Google for their consideration should be done in CSV or text format. Most of us wouldn’t consider using an excel file or Word document. But that is not always the case.

A Google Webmaster Help thread has a web site owner who submitted a Microsoft Word document in the file format .DOCX via the disavow tool upload form. Then they complained that nothing happened in the forum. Google’s John Mueller explained that the file format he used was not supported. John wrote:

So make sure to stick with a CSV or text file for this for now.

Forum discussion at Google Webmaster Help.