Is it possible?

I want to create unique autotags, but not whole plugins.

Right now, I just use something to the effect of
[QUOTE in system/lib-story.php]
$article->set_var( 'unique_tag', unique_tag($A['sid']));
[/QUOTE]
and I have a function called "unique_tag" in system/lib-custom.php

But that way I have to update system/lib-story.php each time a new version comes out. I'd like to manage the whole thing straight from system/lib-custom.php (which I'd update anyway) or something similar.

If not, can I create a dummy plugin?

Have a look at my Flickr plugin. It basically only consist of the autotag function.

Plugins can be pretty minimal. If you ignore the install/uninstall, they can be reduced to just one function.

bye, Dirk