The designator adornment allows notes on an adornment to refer to the adornment's attributes. Only available in an adornment's $OnAdd action and in no other contexts. This is similar to the 'Link type honouring operators' designator.
In this context, using parent would result in the value being taken from the parent of the current map view.
In all other contexts than the above, the adornment refers to the map view adornment(s) on which the current note rests. If the note overlaps two or more adornments, adornment designates the uppermost (front-most) adornment.
If the note overlaps no adornment, then adornment is bound to this. For example, the rule
will change the note's colour to match the colour of an adornment, but leaves the colour unchanged if the note does not overlap an adornment. This latter usage, with an inherent 'if on adornment' switch makes for more flexible coding in maps.