This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
appearance read-only property of the
BluetoothAdvertisingData interface returns one of the values defined by the
var appearance = BluetoothAdvertisingData.appearance;
The definition of 'appearance' in that specification.