Karolinen 1899 Overprint Postal Stationery Ei P1 (99 K) Ei P1 (99 M) Ei P2 Ei P3 (front) Ei P3 (rear) Ei P4 (front) Ei P4 (rear) The first postal stationery produced especially for Karolinen were overprinted versions of German Empire issues. Set Date(s) 1899 1899 Overprint Postal Stationery Ei P1 (99 K) Ei P1 (99 M) Ei P2 Ei P3 (front) Ei P3 (rear) Ei P4 (front) Ei P4 (rear) The first postal stationery produced especially for Karolinen were overprinted versions of German Empire issues. Set Date(s) 1899