Excluding Categories

Thanks for your question. I have had success with this shortcode on my test system:

[mla_gallery]
tax_query="array(
    'relation' => 'AND',
    array(
        'taxonomy'=>'attachment_category',
        'field'=>'slug',
        'terms'=> array( 'new-category' ),
        'operator' => 'IN',
        ),
    array(
        'taxonomy'=>'attachment_category',
        'field'=>'slug',
        'terms'=> array( 'short' ),
        'operator' => 'NOT IN',
        )
    )"
[/mla_gallery]

Of course, you will have to replace new-category and short with the appropriate term slugs from your application.

I have used the alternate “enclosing shortcode” syntax to avoid problems that WordPress has with parameters that include => characters.

I am marking this topic resolved, but please update it if you have problems or further questions regarding the above suggestion. Thanks for your continuing interest in the plugin.