[css-anchor-position] Specify just how invalid bang-important is. #10058

Author: tabatkins

css-anchor-position-1/Overview.bs

@@ -1433,6 +1433,8 @@ the following [=properties=]:
 * 'inset-area'
 
 It is invalid to use ''!important'' on the properties in the <<declaration-list>>.
+Doing so causes the property it is used on to become invalid,
+but does not invalid the ''@property-try'' rule as a whole.
 
 All of the properties in a ''@position-try'' are applied to the element
 as part of the <dfn>Position Fallback Origin</dfn>,