H2 Spatial Tax Pilot: Indentation vs. Explicit Delimiters in Causal Language Models

Pre-registration specification for the H2 Spatial Tax pilot study evaluating scope-closing failure rates in Qwen2.5-Coder-1.5B-Instruct across indentation-only and explicit delimiter conditions. Frozen prior to test task and model generation. Permanent Git tag: prereg-pilot-frozen. ---AI Assistance Statement:The author acknowledges the use of AI language assistance during the preparation of this pre-registration document for language refinement, structuring, and English grammar assistance. The research design, hypotheses, parameters, and final specifications were directed, verified, and approved by the author.