Free accounts can only see 10 articles at a time. As such, the last 10 expired articles will show up in your queue, until they are re-read at which point they will disapear until they are scheduled.
Articles postpone toward the future will not show up at all, until they expire.
However, if you have a Queue, your active Queue article will always be part of your 10 articles
After adding an article, you can select how often it will re-appear in your list, once it is read:
A category is a group of articles, each with their own scheduling option. You might have a "Work" category, a "Upcoming Movies" category and a "Recipe" category (in addition to articles without a category). You can switch between categories at ease.
A label however, is a scheduling option. For each custom label (and the 3 built-in), you get a button to recall all articles with that label for the current category. Until you press that button however, articles with a label remain hidden.
You can mix and match. You could have "Vacation" articles in your "Work" category to remind you of your tasks at work to prepare for your vacation (like how to set an auto-respondor), while your "Vacation" articles in your "Personal" category might be a checklist of what to bring to the beach.
Regardless of which Reccuring Option is selected, you may reschedule an article for any date of your choice. The reccuring option will only take effect after read on the new date.
If you use a fixed date options (like Weekly, fixed day of the week), and you manually reschedule that article, it will move on the day of the week it was rescheduled and lose it's original programming.
For every article, you can optionally specify a count, which is the number of times your article will be read before they are no longer re-scheduled.
If you have an active Premium account, you can easily re-activate an article whose count has reached 0.