Open source software (OSS) sustainability depends not only on code contributions but also on governance structures that define who decides, who acts, and how responsibility is distributed. We lack systematic empirical evidence of how projects formally codify roles and authority in written artifacts. This paper investigates how OSS projects define and structure governance through their GOVERNANCE.md files and related documents. We analyze governance as an institutional infrastructure, a set of explicit rules that shape participation, decision rights, and community memory. We used Institutional Grammar to extract and formalize role definitions from repositories hosted on GitHub. We decompose each role into scope, privileges, obligations, and life-cycle rules to compare role structures across communities. Our results show that although OSS projects use a stable set of titles, identical titles carry different responsibilities, and different labels describe similar functions, which we call role drift. Still, we observed that a few actors sometimes accumulate technical, managerial, and community duties. %This creates the Maintainer Paradox: those who enable broad participation simultaneously become governance bottlenecks. By understanding authority and responsibilities in OSS, our findings inform researchers and practitioners on the importance of designing clearer roles, distributing work, and reducing leadership overload to support healthier and more sustainable communities.

翻译：开源软件（OSS）的可持续性不仅依赖于代码贡献，更取决于治理结构——即界定由谁决策、谁执行以及责任如何分配的机制。目前我们尚缺乏系统性的实证证据，来揭示项目如何通过书面文档正式编码角色与权威。本文探究了OSS项目通过GOVERNANCE.md文件及相关文档定义和构建治理结构的方式。我们将治理视为制度性基础设施——一套塑造参与、决策权与社区记忆的显性规则体系。采用制度语法方法，从GitHub仓库中提取并形式化角色定义。通过将每个角色分解为职权范围、特权、义务与生命周期规则，我们比较了不同社区的角色结构。研究结果表明，尽管OSS项目使用稳定的称谓体系，但相同头衔承载着不同职责，不同标签却描述相似功能——这种现象被称为"角色漂移"。同时我们发现，少数参与者有时会集中承担技术、管理与社区三重职责，这形成了"维护者悖论"：那些推动广泛参与的人反而成为治理瓶颈。通过理解OSS中的权威与责任分配，本研究成果揭示了设计更清晰角色、均衡工作负载、减轻领导超负荷对构建健康可持续社区的重要性，为研究人员和实践者提供启示。