This sidewalk stamp says: "Zarząd Miejski m. Lucka" (Municipal Board of the City Lutsk). This curb dates from the interwar period when Lutsk was part of the Second Polish Republic (1920-1939)
The pre-WWII company Ferrum Lwow not only made manhole covers and storm drains but also manufactured and/or laid cement sidewalks. The stamps served as an identification and advertisement.