Hi,

I am going to make a website with accessible hotels/appartements/pubs/... for disabled persons. I would like to add some "properties" of item/K2 article like parking for disabled person, accessible toilets, special room for disabled persons, etc. How can I manage that other will just click a "properties" of their hotel and then in item will appear icons for that.

Something like this: mojapot.net/apartma/vive-diem-schladming

You can do this with extrafields.
In order to print extra HTML in your template, I would personally render each field seperately.

This code is a good starting point.
github.com/kricore/Advanced-templating-with-K2/blob/master/_inc/cheatsheet.php#L104-L109