So, then I just followed the instruction and clicked the checkbox, which then received a cool red outline. And then, again, I was told what to do next:
When I clicked the textfield, the Connection Wizard appeared (with, in the background, a further instruction for what to do), giving me a click-through set of steps for connecting the checkbox to the textfield:
And all because... I had installed the update to the Matisse GUI Builder (as mentioned here). The internationalization features in the update pack are very cool too. The best description of the update pack can be found here. I found the pack in the 5.0 Beta Update Center, but couldn't find it in the 5.5 update centers.
In other news. Check out Ahmed Mohombe's cool NBClick page! Anyone want to pitch in and help with this project? Sounds really cool, I know I want to be involved.