One of the core Data Validation checks in Tide is ensuring that all values are of the correct Data Types. For example, that a Date is a Date, and a Financial value is a Financial value. 

Yes or No are the only valid values in Boolean fields. Tide uses Data Reference Data validation functionality to correct these values. To do this, Boolean fields are given a Data Type of Reference, and are connected to the Boolean Reference Data Table, which contains two target values: Yes and No.