Open/activate via URL parameter doesn’t working

Hello everybody!

I'm just trying to remember your guide to "Open/activate via URL parameter?
Unfortunately the examples in the FAQ do not work properly...

You should specify the following:

http://example.com/accordions/?active_index=83|1

Does the path "accordions" already belong to it? So you have to include it?
In my case the character "|" is converted in the URL, is this correct?

How do I specify the path to a nested accordion?

Thanks for your help!