[TYPO3-dev] Creating a common hook plugin

[Tapio Markula]

Hi

What could be reasonable is to create a common hook plugin for
some core files

template.php - that file is really core and
it would be nice to create hooks for CSS and JavaScript
in order to add with user-defined class methods (functions) CSS and 
JavaScript
to the HEAD section of page

index.php of User > Setup
adding dynamic new items
saving data of new items.

setting those with hooks would give for all plugin developers more
possibilities to create customizable plugins.

But because I don't understand properly the hook mechanism I need you help.