Trouble searching for credit card / bank account numbers

Regarding the second item -

• But if I search for the last four digits of a credit card number, matches show up only in the dropdown search list, but not in the "Show All Matching Items" list when I hit CMD-Enter. Weird!

This behavior changes based on how the number is stored.

If it is stored as 1111 2222 3333 4444, with spaces, 4444 WILL match.
If it is stored as 1111222233334444, no spaces, then it will NOT match.

Note that it is always displayed with spaces; edit the entry to see how it is actually stored.

AFAICT this is because search only matches at delimiter boundaries, and does not perform substring search. This is painful enough for Titles and URLs, but it's brutal for other fields.

This is likely what's happening to bank account numbers as well.

I deeply hope that substring search returns!