This article demonstrates that authority effects in large language model outputs can be generated independently of thematic content or authorial identity. Building on Ethos Without Source and The Grammar of Objectivity, it introduces the concept of non-expressive ethos, a credibility effect produced solely by syntactic configurations compiled through a regla compilada equivalent to a Type-0 generative system. The study identifies a minimal set of structural markers (symmetric coordination, measured negation, legitimate passives, calibrated modality, nominalizations, balance operators, and reference scaffolds) that simulate trustworthiness and impartiality even in content-neutral texts. Through corpus ablation and comparative analysis, it shows that readers systematically attribute expertise and neutrality to texts that satisfy these structural conditions, regardless of topical information. By formalizing this mechanism, the article reframes ethos as a syntactic phenomenon detached from content, intention, and external validation. It explains how LLM-produced drafts acquire legitimacy without verification and why institutions increasingly accept authority signals generated by structure alone. The findings extend the theory of syntactic power and consolidate the role of the regla compilada as the operative generator of credibility in post-referential discourse. DOI Primary archive: https://doi.org/10.5281/zenodo.16927104 Secondary archive: https://doi.org/10.6084/m9.figshare.29967316