Code cloning occurs when two or more code snippets are identical or sufficiently similar in terms of their structure, syntax, or semantics. When duplicated code snippets are not maintained consistently, cloning can negatively affect software maintainability and introduce defects and behavioral inconsistencies. To track the evolution of duplicates, code clone genealogy extraction involves analyzing successive versions of a software system to identify code clones, their modifications, additions, and deletions. Existing studies on code clone genealogies has made substantial progress on tracking clone groups across versions, but it offers limited support for explaining why clones are introduced or removed in terms of the concrete actions of developers. This study presents a new taxonomy to characterize clone introduction, modification, and removal at the snippet level, grounded in developers’ actions. To evaluate the taxonomy, we outline a two-phase empirical study: a retrospective analysis on open-source and industrial systems to quantify the prevalence of taxonomy categories, followed by monitoring pull requests in industrial projects using event-triggered surveys. We expect this study to provide a clear understanding of how code clones emerge and disappear, revealing developers’ motivations for these actions.