I am using Google Custom Search along with the XML API. From the documentation linked below, I can see that the XML API supports searches for .xls files, but what about .xlsx files? Half of our files are now the newer .xlsx format and we need for them to turn up in our search results.
How does one search for .xlsx files with the XML API? This is not covered anywhere in the XML API documentation and searching for .xls files does not return any results for .xlsx files, when it should.
https://developers.google.com/custom-search/docs/xml_results
I figured it out. You can use filetype:xlsx even though the documentation does not include xlsx as a supported file type to search for.
Also, you can search for multiple file types. Here is the documentation on that: https://developers.google.com/custom-search/docs/xml_results#wsSpecialQueryTerms