This study presents a conceptual framework for informal preservation, redefining digital heritage preservation beyond institutional models. Drawing from interdisciplinary research, it constructs an informal preservation scheme that demonstrates how digital heritage is sustained not only through structured conservation but also through decentralized, adaptive, and participatory practices. Among these, tacit preservation plays a crucial role, sustaining digital heritage through collective participation and continuous reinterpretation. Rather than treating preservation as a fixed process, this study examines how it unfolds dynamically, embedded in the circulation and transformation of digital artifacts. By reconsidering preservation as an adaptive, networked phenomenon, this research highlights the impact of distributed memory practices in shaping the future of digital heritage in the post-digital era.