When using atomic operations, explicitly justify the choice of memory ordering. Each use of a memory ordering should be documented with a clear explanation of why that specific ordering is sufficient and safe. Key guidelines: - Use Relaxed for simple counters without synchronization needs - Use Acquire/Release for establishing happens-before relationships - Avoid mixing SeqCst with other orderings - Document safety assumptions for weaker orderings Example: ```rust impl Clone for Sender { fn clone(&self) -> Self { // Relaxed is sufficient for incrementing the reference count // since no synchronization is needed - the sender is already // guaranteed to be valid when Clone is called self.shared.ref_count.fetch_add(1, Relaxed); Self { shared: self.shared.clone() } } } impl Drop for Sender { fn drop(&mut self) { // AcqRel ordering required for reference count decrement // to synchronize with other threads that may be checking // if this is the last sender if self.shared.ref_count.fetch_sub(1, AcqRel) == 1 { self.shared.close(); } } } ```