Smoking gun indicator that these names were just added in a batch mode en mass from some data list. If added by a worker at a computer the registration date would have defaulted to the entry date or have been required to be sntered from a date on the form. In either case it would not be the 1918 default.
Ok, read the link in 2 and these were due to batch inserts where the county legacy system didn’t have a DOB. I knew they had to be batch inserts.