...and that's just A through L and the beginning of M!

The Polish State Archive at Poznan has uploaded over half a million
images--about 250,000 two-sided cards--of the city's residence
registers. These list all the members of a household, usually with
vital events plus dates and places of arrival, departure, etc. Sometimes
parents are listed too. The amount of information on just one of these
cards can be staggering--dates of birth, death, marriage, etc. for a
whole family, and where to look for them before or after they lived in Posen.

http://szukajwarchiwach.pl/53/474/0/19.3/14652/str/1/6/100#tabSkany
will show you an example of what I'm talking about.

The population of Posen was almost 11% Jewish in 1880; about 5% in
1903. 7,000 Jews in 1880; 5,000 in 1903.

Gdansk has published a smaller collection of these already, and I know of
several other cities in today's Poland for which these cards have survived.

Roger Lustig Princeton, NJ research coordinator, GerSIG Prussian
Poland area coordinator, JRI-Poland GerSIG.Research@...