Kingdom of Loathing Certificate of Participation
From A KoL Wiki

Kingdom of Loathing Certificate of Participation
The Kingdom of Loathing Certificate of Participation is a furnishing located at your Campground.
Notes
- Obtained by using a Certificate of Participation, which is in turn obtained as a reward for having completed the Toot Oriole Quest.
- View your Certificate every day for a little KoL pick-me-up!
- The Kingdom of Loathing Certificate of Participation is not affected by ascension; you do not have to re-obtain it in your next incarnation.
When "Used"
Your Kingdom of Loathing Certificate of Participation hangs proudly, declaring to all who view it that you are, indeed, a participant in the Kingdom of Loathing. Go, you!
Shiny Certificate
It is possible to obtain a shiny version of this certificate, using it gives the folowing message:

Your Kingdom of Loathing Certificate of Participation hangs proudly, declaring to all who view it that you are, indeed, a participant in the Kingdom of Loathing. Go, you!
It's shiny because you've been to one of the official KoL Conventions.
It is rumoured to have appeared after people visited a test page.