The Kosner Manual doesn't appear to be a widely recognized term or concept. However, I can try to provide information on what a "manual" typically entails and see if I can find any relevant information related to "Kosner."
If you could provide more context or details about the "Kosner Manual," I may be able to assist you better.
If this was a speech-to-text error, you might mean — a guide to kosher dietary laws (kashrut) in food production.
There is a known historical reference: (often spelled Kossner or Kösner ) — a rare or privately published manual related to early 20th-century watchmaking, precision mechanics, or optical engineering , possibly from German or Swiss origins.