This skill defines safe refactoring patterns (RF-001 through RF-006) for improving ADVPL/TLPP code structure without altering behavior: extract function, simplify conditionals with guard clauses, remove dead code, improve naming to Hungarian notation, eliminate duplication, and reduce function parameter count. It also defines the mandatory process -- analyze, prioritize, present a before/after plan, wait for user approval, apply one change at a time, verify -- and hard safety rules (never change business logic, never rename externally-used symbols without a caller check).

Activate this skill when the user wants existing, working code restructured for readability or maintainability: long functions, deep nesting, unclear names, copy-pasted blocks, or functions with excessive parameters. It does not cover fixing bugs or errors (see ), generating brand-new functionality (see ), a formal quality/security audit (see ), or converting procedural to object-oriented (see , which is a structural paradigm change rather than a behavior-preserving cleanup).