ListDataFormat.AllowFillIn Property (Excel)
Returns a Boolean value indicating whether users can provide their own data for cells in a column (rather than being restricted to a list of values) for those columns that supply a list of values. Returns False for lists that are not linked to a SharePoint site. Also returns False if the column is not a specified as choice or multi-choice. Read-only Boolean.
Syntax
expression .AllowFillIn
expression A variable that represents a ListDataFormat object.