From BS 1192 and PAS 1192 to ISO 19650. More information can obtained from this link: https://www.thenbs.com/knowledge/from-bs-1192-to-iso-19650-and-everything-in-between- Also the ISO document can be purchased here: Part 1 - https://www.iso.org/standard/68078.html Part 2 - https://www.iso.org/standard/68080.html
Excerpt from BIMForum's 2017 LOD Specification: The BIMForum’s interpretation of the LOD definitions are as follows: LOD 100 elements are not geometric presentations. They may be symbols or other generic representations of information that can be derived from other model elements. Any information derived from LOD 100 elements must be considered approximate. LOD 200 elements are represented graphically but are generic placeholders, e.g., volume, quantity, location, or orientation. Any information derived from LOD 200 elements must be considered approximate. LOD 300 elements are graphically represented as specific systems, objects, or assemblies from which quantity, shape, size, location, and orientation can be measured directly, without having to refer to non-modeled information such as notes or dimension call-outs. LOD 350 elements are enhanced beyond LOD 300 by the addition of information regarding interfaces with other building systems. For example, ...