Redlining

I won't soon forget Ben handing me the first of those printouts, literally covered with his notes, arrows, X's, redlinings...My heart sank.

Source: wiktionary

Admittedly, our metropolitan plan was an exercise in hope. There were million reasons why it might not have worked. But it represented a responsible way to try to begin atoning for the public housing ghettos, the racial zoning and covenants, the redlining, the “Negro removal,” and the other policies and practices that had given us the two separate and unequal societies described by the Kerner report.

Source: wiktionary