Didn't I already wrote to you about this? Maybe it was someone else...
Anyways, there is an option in text editor on Peakd.com called "Spoiler" it adds the code for this feature. It doesnt work well on ecency, but only on peakd.
the actual code for my list is like this:
Previous participants:
>! [Click to see the list of previous participants] Previous participants:
> <sub>names....