I think I figured something out. The only reason I'm writing the list
about it is because it may help others out with similar situations. I can
put ($) in headings were columns contain all currency figures. That would
normally be a prefix to those numbers so I might write ($) amount as a
column heading but I would not be surprised if I got an org-mode
spreadsheet with a heading like performance (%) in it and could understand
that all entries in that column were percentages. This may be a way to
handle both prefixes and suffixes in spreadsheet applications for org-mode
in the future.