Thanks for your reply. I've been trying to find out exactly what makes it possible for the qet_tb_generator plugin to notice that a terminal exists in a project and include it in the terminal block which it compiles and after much trial and error I think I have discovered it. Perhaps this is documented somewhere but I couldn't find it so I will write it down here for the benefit of others.
construct an element which contains (at least) one terminal and set its Base type to Terminal block (in Edit / Element Property);
add (at least) two of these to a folio;
make at least one connection between any two of them with a conductor;
if for each element the element property Label is given a value which has the correct format (something like <alphanumeric>:<alphanumeric>) then the plugin will find and list that element.
Something odd happens when I call the plugin (using Project/Launch the terminal block creation plugin) - it always throws up the error message box titled "Error launching qet_tb_generator plugin" which details how to install the plugin before it then successfully runs!
Thanks for your work on this project. I have no experience with such a tool but first impressions tell me that this is a very comprehensive piece of work, well done!