Controls whether the argument is optional.
This property controls whether the argument is defined as optional, and when it should be treated as missing, in which case the DefaultValueText is used. It may contain any or all of the following flags:
| Flag | Description |
|---|---|
| MissingOrEmpty | Argument has been omitted completely from the formula, or is an empty cell. |
| Blank | Argument is a blank cell, containing the string returned by
="". |
| Zero | Argument value is zero. |
| Nonnumeric | Argument value is not numeric. |