Imagine, if you will, a matrix report. . .
You’re grouping by Account, but pulling in the Account Name via the Report Type layout, or perhaps a cross-object formula. And what happens? All your Brown Households get smooshed into one big Brown Household. A very generous household, based on the data, but not a very useful report. (How do you know if this is happening to you? Check the detail on your report, maybe, or check your totals against household records.)
Building on the ideas of the Hidden Hyperlink and the Secret Sorting post from last week, you can create a formula field that will act as a unique name even when pulled across objects:
HYPERLINK("/sort=?"& Name, "")& HYPERLINK("/"& Id , Name)
You still want it to sort by name, which is what the first, empty hyperlink is for — without this part, the field would sort on the SFID. The second hyperlink contains the record id, making this “Name” unique and ensuring that households with the same name don’t get grouped together.
This exact formula should work to create a Unique Name field for any object where cross-object grouping is needed.