If you are creating a report or group based on whether a field is or is not populated with data, you will most likely be using the null and/or empty conditions.

Is Null = Absolutely no data in the field whatsoever (In Novi Groups, null includes both the null and empty condition)
​Is Empty = could contain non-visible or empty data such as a space or "  " (Empty is only available in custom reports)

So, if you want to create a report, for example, of everyone who HAD a Designation or Credential listed in their record you would set the conditions below: