Contributed a targeted documentation update to the JuliaSymbolics/Symbolics.jl repository, focusing on the substitute function’s fold parameter. The work clarified how the fold option determines whether expressions are evaluated during substitution, providing a detailed description and a practical example using fold set to false. This technical writing effort, implemented in Julia and leveraging documentation tooling, aimed to improve API clarity for users working with symbolic expressions that should remain unevaluated. By enhancing the documentation, the contribution accelerated user onboarding, reduced potential support queries, and increased reliability for those utilizing advanced substitution features in Symbolics.jl. No bug fixes were addressed this period.