Lebenszeichen "Sign Of Life" From Germany

This card came in a lot of stationery type postal cards from Germany. As best I can tell, it is looking to certify post war survivors, with lebenszeichen translating to "sign of life." Anyone know anything about these?

These cards were issued in 3 colours:

Explanation in short.

Time period is mostly 1944

Red: For civilians to notify somebody after a Bombing that one was still alive.

Green: to notify a soldier(Had to have a Fieldpost number) that one was still alive.

Purple. An express way to notify people, that one was still alive. I believe they could be used by both civilians and soldiers.

I am sure other members will add pictures and additional information.

Kind regards, Johan

We should use those cards again but printed in English .We can give them to college students so they notify their parents ,that they are still alive .

Thank you,Johan.

Thanks for the answer Johan.

The small text on the bottom right StdW. 4305 43
means it was printed at the Staatsdruckerei Wien - Stateprinter Vienna,
initial printing 1943.

Thank you for the additional information, lithograving.

The geniuses behind this board decided to move this post from general discussion to the 'picture postcard' forum. For anyone wondering, I did not mispost this, it was moved here. Now anyone not interested in picture postcards will be unable to see it. Simply genius.