An EventIdentifier specifies a criteria for matching input events using a relaxed form of the
NormalizedEventIdentifier syntax. Each EventIdentifier corresponds to one or more
NormalizedEventIdentifier values.
In addition to the phase being optional, the modifiers may be specified in any order. If the
phase is not specified, then the EventIdentifier matches both the 'at' and 'bubble' phases.
An EventIdentifier specifies a criteria for matching input events using a relaxed form of the NormalizedEventIdentifier syntax. Each EventIdentifier corresponds to one or more NormalizedEventIdentifier values.
EventIdentifier ::= [ phase ':' ] ( modifier '+' )* base-event-identifier
In addition to the phase being optional, the modifiers may be specified in any order. If the phase is not specified, then the EventIdentifier matches both the 'at' and 'bubble' phases.