Thanks to Alex Popescu for pointing me to this nice post from Wai Hon about marking repeated tasks in the agenda listing. Why would you want to do that? Han explains it in his post: if you mark a repeated task as done but forget to readd the repeater, the task can disappear. Marking agenda tasks as repeated helps to prevent that.
Fixing the problem is pretty easy but involves a few lines of Elisp. Take a look at Han’s code for the details. It’s only a few lines and relatively simple. If you object to having to use Elisp, Han provides a couple of alternative solutions one of which doesn’t involve writing Elisp.
One could dismiss all this as a non-problem or at least a problem too small to worry about but we Emacers are all about reducing friction wherever we find it and this is a nice example of that. Regardless, if you sometimes find yourself having to base your next action on whether or not the current task is repeating, take a look at Han’s post.