? "EK." - Petrus J. F. ten BOSCH – dutch

Dokumente Schreibstubenkarten aus Buchenwald
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Any idea about the meaning of „EK“ in this context? (top center)

Petrus Joannes Franciscus TEN BOSCH

more info here and on zooniverse-ENC here and here (thanks to @velthove1 and @carola.b)