Hi Hans, After struggling to set up a complex structure with \defineblocks in which I wish to have a series of exercises (with a certain number of questions) and hints (some questions have no hints, ans some exercises have no hints), and finally solutions (again some questions have no answers, and some exercises don’t have solutions), I remembered that a few years ago you talked about a coupling mechanism in mkiv. As a matter of fact in the file strc-enu.mkvi this coupling mechanism is introduced but I didn’t figure out how to adapt it to my needs, that is to the situation I just described. Is there an example which can help understand how to use it? Is it possible to submit a feature request (for instance automatic interactions between each component, say exercise, its hint and its solution), with a reasonable amount of effort on your part to have it? Thanks in advance, and please forgive me if I am pushing too far my request… Best regards: OK