I was in Eskişehir during the Feast of Sacrifice (Kurban Bayramı), these pictures show some of the preparations: getting the sheep home, notices of the city indicating where one might perform the ritual in designated areas (though I saws several instances of slaughter in private gardens or just along the side of the road, that seemed to be forbidden now in most places).
This poster was explained to me: Mehmetcik is the nickname of the Turkish soldier. Mehmetcik Vakfi means Mehmetcik foundation. It provides support to the families of the fallen soldiers and soldiers who have been incapacitated in the line of duty. The poster is basically solicitating for support to the Mehmetcik Foundation during the Kurban Bayrami. People are being invited to send their donations to the foundation.