I have a a number of picture postcards (collected for pictures of German Generals in WW1). Four are addressed to Sergeant L. Ingelse in Haag, Holland. No message as all were sent at the printed matter rate of 5Pfg. from Germany. All have a double-circle cachet for a firm in Seitendorf, near Dresden. Postmark also for Seitendorf. Two types of cachet for Emmerich, a town a short distance from the Dutch border. This was to show that the card was going to a foreign country and censored. Also, Dutch receiving (censor?) mark.
Was Sergeant Ingelse interned in Holland (German or Belgium)? Was a Belgium worker in Germany writing to a Belgium soldier interned in Holland?