What does the "cdw" do exactly in the canned Search for "Recents"? The Finder's sidebar search for "Recents" (in High Sierra) is a raw query, which can be found here:
            /System/Library/CoreServices/Finder.app/Contents/Resources/MyLibraries/myDocuments.cannedSearch/Resources/search.savedSearch.  

The query string goes like this:

(kMDItemLastUsedDate = "*") &amp;amp;&amp;amp; ((kMDItemContentTypeTree = public.content) || (kMDItemContentTypeTree = "com.microsoft.*"cdw) || (kMDItemContentTypeTree = public.archive))


This also looks for Microsoft stuff.  The relevant part of the query is:
    kMDItemContentTypeTree = "com.microsoft.*"cdw

What does the "cdw" part of this query accomplish?  And what does it stand for?

I found another mention here for mdfind usage:
https://gist.github.com/cwalston/7425465

!   -interpret        Force the provided query string to be interpreted as if the user
!                     had typed the string into the Spotlight menu.
!                     For example, the string "search" would produce the following
!                     query string:
!                     (* = search* cdw || kMDItemTextContent = search* cdw)
The cdw at the end of the query string means the comparison should ignore case, diacritics, and width (which is mostly relevant for text with Asian characters).

1st source: How can I find files by content in mac os x?  


  Use this modifier... To specify a comparison that is...
  c                             Case insensitive.
  d                             Insensitive to diacritical marks.
  w                            Word-based. In addition, the comparison detects transitions from lower-case
                                 to upper-case.
  t                              Performed on the tokenized value. For example, values passed directly from
                                 a search field are tokenized.


2nd source: CSSearchQuery