Hi,

This can be added by a simple <SCRIPT type=text/javascript src=..../> in the HEAD, leaving the choice of the lightbox/javascript-framework combination to the board's administrator.

We consciously avoid a JS framework. But of course, the forum administrator can be add ANY library and he can modify the exiting code...

The problem is the necessary PHP-coding providing the FORM for entering

No, not necessarily. The forum administrator can add a self-written javascript, which selects the images and modify the DOM, too.

regards
Micha