attachment extension check
 

Where is the attachment extension check upon attachment upload located? I've searched through several templates, such as newattachment, but cannot find it. It doesn't seem to be located in attachment.php neither.

Thanks in advance.

Admin CP => Attachments => Extensions & Sizes

This is where you select what attachments to allow. Is this what your looking for, or are you trying to edit how it checks it in the code?

I'm actually trying to edit how it checks the code :)
I currently have a gallery installed on my forum which parses both files and images, so would like to create plugin that allows me to define specific allowed extensions for the gallery enabled forums.