the pipeline insert_js is called two times with a different argument {{{$flux['type']}}} that request injection of inline or file scripts;
{{{$flux['type']}}} can be "inline" or "fichier";
Inline call makes it possible to inject scripts:
1) that cannot be packed because of limits of the php compressor
2) that are templates themselves, therefore needing a specific {{{<script src="spip.php?page=....">}}} tag
3) that is better to view as part of the head rather than to be consolidated in jquery.js.html