Serendipity Forums

That depends, if you want to have the PHP output to sidebar or content area. For the first install in sidebar plugins, for the latter in event plugins.

And NO, the permalink path is the "staticpage like" path, the path under which your content is readable.
The name is for URL rewrite purposes and for plugin branding
and the include file path for ...!

This is the main issue:

i need to know what is the way in Serendipity! I need to know how to show content in the blog area or it has no sense to use a blog and no other pages.
So what do i have to type in permalink to show php pages in the blog area?

You could just test it yourself, couldn't you?

Permalink ie. "/pages/collaborations.html" (this is virtual - the URL)
Name "collaboration"
Include path "/the/full/path/to/your/php/file.php"

Access via http:// fireofdarkness.altervista.org/pages/collaborations.html
Output in #content area.

Note: Serendipity is mainly a blog system, designed for this purpose. Things like extra php pages etc are just additions to make its usage more CMS like. So you will have to think about ... what you really want to do with it.