DUID

These are your human readable Dataset Unique IDentifiers. 

A system generated human usable unique identifier that does not appear on the printed documents, welders or reports. It follows the format-

<Entity Type>-<Date in YYYYMMDD>-<incrementing #>

so for example-

Welder-20151210-1
WPS-20151210-2

This field will be unique for each PQR, WPS, WPQ and Welder in your database but will not be unique across all ProWrite databases in the world.