Found this on another board:
"Hi Denis,
I must admit... the SpecialCells method can be a little
bit tricky. I have prepared a summary below explaining
what each of the types are - and when they will work.
I hope this helps!
Cartman
Summary
xlCellTypeAllFormatConditions - This function will "work"
if the specified range contains any conditional
formatting. Any cells containing conditional formatting
will be selected out of the specified range. If no
coditional formatting is implemented, you will get a run
time error '1004'.
xlCellTypeAllValidation - This will only work if there is
data valadation in place in the specified range. Any
cells containing data validation will be selected form the
specified range. If no data validation is implemented,
you will get a run time error '1004'.
xlCellTypeBlanks - This will only work if a blank cell
exists in the specified range... It will select any blank
cells in the specified region. If no data blank cells are
within the specified range, you will get a run time
error '1004'.
xlCellTypeComments - THis will only work if a comment is
attached to a cell within the specified range. All cells
containing comments will be selected. If no cells contain
a comment, you will get a run time error '1004'.
xlCellTypeConstants - this will only work if a cell
contains a constant in the specified range. All cells
containing constants will be selected. If no cells in the
specified range contain a constant, you will get a run
time error '1004'.
xlCellTypeFormulas - this will only work if a cell within
the specified range contains a formula. All cells
containing a formula will be selected. If no cells in the
specified range contain a formula, you will get a run time
error '1004'.
xlCellTypeLastCell - this will select the last cell that
was used in the specified range. This is somewhat
decieving... suppose you had once put something into cell
ZZ500. But now, your current "range" only goes out to
C4. If you called Worksheets(XXXX).Cells.SpecialCells
(xlCellTypeLastCell).select - it would select ZZ500!
xlCellTypeSameFormatConditions - this will select all
cells in the specified range that contain the same format
as the *first* cell specified in range. If the first cell
specified in the range does not have conditional
formatting - you will get a run time error '1004'.
xlCellTypeSameValidation - this will select all cells in
the specified range that have the same validation scheme
applied as the *first* cell in the range. If the first
cell in the range does not contain data validation, you
will get a run time error '1004'.
xlCellTypeVisible - this will select all the visible cells
in the specified range. If all the cells in that
specified range are not visible, you will get a run time
error '1004'"