Qualcomm Quick Charge: A proprietary fast-charging standard found on many Android phones with Qualcomm chipsets; recent versions are largely PD-compatible.
Fast-charging standards work by having the charger and device communicate over the data lines before power flows at full rate — the charger asks what voltage/current the device wants, and the device asks what the charger can supply. Only when both agree does higher-wattage charging begin, which is why a cable without proper data lines can silently cap charging speed.
Compatibility check
Look for explicit Qualcomm Quick Charge branding on both the charger and cable packaging — generic ‘fast charging’ claims without naming a standard often mean a proprietary, narrower compatibility.