LLMON: An LLM-Native Markup Language, now in Granite 4.1 3B and 8B

LLMON (LLM Object Notation) is a new markup language designed to explicitly communicate structure and semantics to large language models. It addresses the brittleness of models that rely on formats like JSON by using reserved special tokens to create an unambiguous, XML-like structure. A key benefit is the mitigation of prompt injection attacks through the explicit separation of instructions and data payloads. IBM has released two experimental Granite 4.1 models trained to use LLMON, along with a toolkit for converting existing JSON structures.