Sometimes the names of those being buried in an epidemic were not known to those recording the event, or they forgot to ask, or to write it down. In the Braddan burial records of 1725, where the number of burials in a short time suggest an epidemic, is recorded the burial of 'A young woman fil William Quine, Place 9 May'. At least we know she was William Quine's daughter - but which one?
In the middle of a serious epidemic, there may not have been time, especially when mass graves were being used, and the names never got recorded. In St Erth parish church in Cornwall, there is an MI to 'Six victims of the smallpox'.
In the days before passports, hotel registers and driving licences, of course, visitors dying suddenly while traveling quite often got buried with no record of their name.
Roger