[Ger-Poland-Volhynia] Numbers on the Ships Manifest

[Michael & Maureen McHenry]

Hi All

I often see on ships manifests numbers that have been written by
different hand. They also have a date next to them usually late 1930's
to early 1940's. It seems peculiar to emigrants from Eastern Europe. I
also do Irish genealogy and never seen one on them. One I saw today was
1-298374  5-21-1940. Does anyone have any idea what this was done for?

                                 Mike