HairAccessory is a comma-separated list of asset IDs that determine what accessories should be added when the description is
Humanoid/ApplyDescription|applied, usually those attached to its head resembling hair. The list is kept sorted in descending order without duplicates.
Any accessory can used in this property, even if it is meant to go in a different accessory spot. For example, an accessory meant to go on your back (such as a cape) could be included in this property. An error is thrown if you try to apply a new description which shares any assets with the existing description but a different accessory property.
articles/HumanoidDescription System, for more information on HumanoidDescriptions
HumanoidDescription/WaistAccessory|WaistAccessory, which are similar properties that apply accessories like this one