We are approaching the fiftieth anniversary of the publication of two seminal documents for the construction industry: "A Tentative Proposal for a Manual of Practice for Specification Writing Methods", and "The CSI Format for Building Specifications". The first led to the publication of CSI's first Manual of Practice (eventually becoming the Project Resource Manual), the second to MasterFormat.
Although MasterFormat is more widely known and used, the original Manual of Practice (MOP) embodied the essence of CSI's raison d'être - clear communication in construction documents. Along with MasterFormat, the MOP provided impetus for CSI's growth through the end of the twentieth century, as design professionals across the country sought to improve their specifications. Despite its relative obscurity, I believe the MOP's significance was second only to MasterFormat and AIA's contract documents in the world of building construction.