REQUIRED FIELD
When you set a column to be required in the Column Options, it is possible that there are existing records that do not contain a value for this column. This is always the case if you are adding a new column to a data set that contains records. When this happens, you will be required to set a Default Column Value for all records in the data set which do not already contain a value for this column. Each data set will then be modified to contain that value.
Due to the way that the default value is set for each record, you cannot enter a default value longer than 255 characters.