Again, I filtered the over 1,500 collections down to Massachusetts collections (see Post 2), and noticed that some of the collections are "Browse Images." These collections are NOT INDEXED!
This is why you have to do more than a Global Search for names, locations, dates, relationships, etc.! A Global Search will not find entries in the "Browse Image" record collections on FamilySearch.
I picked the "Massachusetts, Plymouth County, Probate Records, 1633-1967" record collection to look for "Seaver" or "Sever" entries. I right-clicked on that collection link, and the collection search page opened in a new Tab:
Since the only way to search this record collection is to Browse, the user has to click on the "Browse through 302,640 images" link. I did:
The screen above shows the different items in this record collection. Each Item represents a volume or "book" in the Probate Record collection. These are called "Waypoints" by FamilySearch - they point the way to the actual records.
There are Dockets by Year Range and alphabetical surname, and then by Probate Case File numbers, and then Probate Court volumes. The Dockets are indexes for Probate Case File numbers and Probate Court volume/pages, and the Probate Case Files contain images of the original papers in the File.
I chose the "Dockets, 1686-1881 Pra-Sta" item, and saw the first page of this "book:"
I managed to find the page with "Sever" Dockets listed, as shown below: