It seems that the Autofilter function does not recognize populated cells that
have been formatted as merged when filtering on blanks. My guess is that
only the first cell is seen as " being filled in". (As the message suggests
when initially merging multiple cells into one, will only keep the data in
the upper-left most cell.) I don't understand why, once the cells have been
merged as one, they are not treated as one by the Autofilter, but it appears
that if there are 5 cells merged as 1 and populated, then the column is
filtered on blanks, the filter interprets the cell as blank. Is there a way
around without complicating the use and maintenance of this spreadsheet as I
am not the exclusive user?