This topic is continuation of https://forum.plantuml.net/12180/unable-to-add-arrow-text-description-after-backward-keyword.
I would like to ask you to add arrow description to object 'foo'. The description back to the 'foo' action can be executed as for elsif, i.e. (incoming description) elseif (condition) else (outgoing description)
(incoming description from backward) repeat :foo;
repeat while (Valid?) is (No) not (Yes)