textual completion

["Mark L. Copper" <ad8854 wayne edu>]

Hi all,

Is there a way to turn the automatic textual completion off?  For
example, when I'm filling in grades on a class roll, one student may
have an "A-" while the next may have an "A", but unless I go back and
edit it, the spreadsheet, like good ol' Clippy, will assume I *must*
mean to give the second student an "A-".

Is this documented somewhere?

Mark Copper