A chandelle is more than a climbing 180-degree turn with a fanciful French name that flows trippingly off the tongue. (Actually en Français, it's just "candle".) Having tactical origins over Europe during World War I, it is one of several required performance maneuvers in the single-engine commercial pilot Practical Test Standards (SEL only; Section 1, Chapter V).
The Aviation Safety Reporting System (ASRS) recently received a report from a concerned Air Traffic Controller (ATC) who describes a non-standard communication practice by pilots and ATC: Using microphone clicks as a response to clearances (by pilots), or to read-backs (by controllers).