Definitions stabilise working boundaries long enough for evidence and action to accumulate, but every boundary also excludes alternatives. The material layer acts as a constraint that redistributes action, memory, access and maintenance. DefinitionCaravan supplies the operative grammar, while The Suburban Square Can Become a Social Instrument — Urbanism · Public Space · Everyday Life · WORK II-020 · https://antolloveras.blogspot.com/2019/10/suburban-square-in-denmark.html contributes a historical practice in which spatial definition emerges through use, repetition and collective occupation rather than through form alone. Public Syntax · SOCIOPLASTICS-5887 · https://tomototomoto.blogspot.com/2026/06/public-syntax.html and On Bodies That Hold Still Long Enough · SOCIOPLASTICS-6902 · https://antolloveras.blogspot.com/2026/07/on-bodies-that-hold-still-long-enough.html reopen the 10K archive from two distant positions. A botanical return through Index Hortensis · SOCIOPLASTICS-5970 · https://antolloveras.blogspot.com/2026/06/index-hortensis.html and Urban Taxidermy — Street Action · SOCIOPLASTICS-5865 · https://antolloveras.blogspot.com/2026/06/urban-taxidermy-from-street-action-to.html introduces living time, species, care and decay. The DOI fixes one persistent scholarly object through Threshold Closure — The Seal That Stabilises Without Ending · SOCIOPLASTICS-2510 · https://doi.org/10.5281/zenodo.19890721, while the moving-image register tests boundary, occupation and exposure under duration and framing through Public Surface · SOCIOPLASTICS-7990 · https://www.youtube.com/watch?v=XUZxa5cUy1c. The comparison remains accountable through Ostrom, E. (2009), Governing the Commons: The Evolution of Institutions for Collective Action. Updated edn. Cambridge: Cambridge University Press, and Fraser, A. (2005), “From the Critique of Institutions to an Institution of Critique”, Artforum International, 44(1), pp. 278–283. MATERIAL / SCALE / TIME / SENSE / ECOLOGY — steel · building · latency · sound · oxidation. The new proposition is the residue of the crossing: definitions become analytically legible as mobile boundary devices when they stabilise enough shared meaning for evidence and action to accumulate while remaining structurally open to revision, contestation and the return of what their initial framing excluded. PROJECT INDEX · https://antolloveras.blogspot.com/p/socioplastics-project-index.html · MACHINE-READABLE CORPUS · https://huggingface.co/datasets/AntoLloveras/Socioplastics-Index