Vets-100A Audit Reports

I'm struggling with understanding the Vets-100A audit reports.  They show some employees with a blank veteran status (meaning the status was not entered).  When I enter a status of Not a Veteran and rerun it, the report numbers are not changing.  Does the report count blank fields the same as if the field said Not a Veteran?  A

I'm also struggling with what the Veteran category L through T means.  Some employees have as many as 4 different rows - each with a different letter in that column.

We are on 11.5.10.

Thanks!