MCP
From Just Solve the File Format Problem
MCP (Monu-CAD Plot) is one of the file formats used by the Monu-CAD monument/headstone design program along with MCC, MCD, and MTN, as well as FNT (fonts), which are stored in the same format as MCD. There are Lite! and Pro versions of the software.
MCP is the format of plots. These are stored in HP-GL format.