So, in Liferay we have a
I can see
top_js.jspf file, but nevertheless it remaind unclear to me.
Thanks in advance.
Liferay's portal.properties is one of the best documented files. You'll find it either in the Liferay Wiki or in portal-impl.jar.
The following sections (in order to not copy everything here) might also contain interesting information for your case. But I guess your question is answered with the parts from above - read the rest in portal.properties.
Edit: To answer to your comment: The order is documented above, it's top to bottom, as the later files depend on the earlier. Further the following property might give a hint on reasoning:
And while one can argue about the amount of documentation for Liferay in general, I'd say you can't argue about portal.properties being among the best documented files in Liferay. Take a look at it - just doing so will give you a lot of insight of what neat things you can do with Liferay.