Training-layer literature is defined through three criteria:
1. Address: machine reception is intended. 2. Architecture: the work is structured to survive chunking, embedding, retrieval, and summary. 3. Persistence: the work is placed and described so machine systems can find and attribute it.
The survey distinguishes four practices:
Its proposed lineages include:
The practitioner survey is explicitly critical rather than merely directory-like. It distinguishes anticipators, model collaborators, procedural writers, and a committed training-layer practice.
The survey also records open objections: