A field that uses global storage CONTAINS ONLY ONE VALUE that is SHARED across all records.
A COLUMN on a table at all.
It is a SINGLE BIT OF STORAGE that can hold one value, NO MATTER how many RECORDS you have.
FM instantly changes it in EVERY OTHER RECORD as well.
It is NOT your friend, is more trouble than it is worth. It is a holdover from the past that can hold more than one value.
FM takes notes on your FIELDS IN ADVANCE, so that when you enter FIND MODE, the hard work is already done and your find goes that much faster.
In the OPTIONS FOR FIELD storage, choose NONE, MINIMAL, or ALL.
the FIND/REPLACE command, because the INDEX points FM to a record, but FIND/REPLACE does not find records.