Kerala's K-Smart application is introducing a 'building card' and 'Digi Door PIN' to address issues arising from delimitation-related address changes. The building card will store historical building numbers, tax details, and pending arrears. The Digi Door PIN will assign a unique, permanent number based on geotagged coordinates, integrating utility databases like water and electricity. This aims to eliminate the need for residents to update documents after ward delimitation cycles.