I would like to be able to add some notes to the timing diagram. For concise participants this could be usefull, if some state is only active a very short time, but needs a longer explanation.
Also, I would like to explain, why a state changed in a note just at the state change.
Syntax suggestion:
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
@0
WU is Idle
WB is Idle
@100
WU is Waiting: THIS TEXT SHOULD SHOW IN A NOTE ABOVE THE MIDDLE of the < Waiting > - bar
WB is Processing
WU note THIS TEXT SHOULD SHOW ABOVE THE STATE CHANGE AT T=100 AND COULD EXPLAIN WHY THE STATE CHANGED
@300
WB is Waiting
@enduml