Hi Scott and Ros,
I understand and aware of radio button "Not Living", but still - it doesnt work until date is provided. BEFORE 1778 - is a date value - which is incorrect. There is a huge difference in genealogy betwen Null value and "BEFORE 1778". When exporting data to Myheritage or Geni and making my trees alligned - those systems are cleverly extimate dates on the fly based on surrounding profiles.
Here is example of Difference betewen BEFORE 1778 and null:
If lets say we know Mariage has happened in 1778 (or any other document), we can attach document to profile and put Birth = BEFORE 1778 - because - he could potentially be agreed to be married as a baby or marry by himself in any date during any age of his life before 1778.
If we know nothing about this profile, except of story and notes without dates, than birth date = Null.
As you may see difference is - Null - we dont know anything, BEFORE 1778 - for any real facts that can prove he was already born before this date!
This is purpose of BEFORE or AFTER in gedcom and other applications.
But here, in Wikitree its wrong by validation form setup. Everybody recommends to put estimations and Null is not allowed. If we buld such estimations to let say 3 generations in a row to ancestors - we will introduce error and confusion. Let say we put Fateher = BEFORE 1778, then Grand Father = BEFORE 1778, than Grand- Grand Father = BEFORE 1778 - they all will be same date. Did you notice repeated value? Because you cant shift estimation! Than if by any chance we discover brother of grand grand father, lets say = 1750, it ruins whole logic and reqires reupdating all subsequent profiles of all (grand-grand, grand, and father). Instead - good practice will be to have radiobutton "Not Living" and dates as blank. Like in all other systems and gedcom