Media Categories

Allows users to assign categories (or other taxonomy terms) to items in their Media Library with a clean and simplified, searchable version of the standard category meta box.
The “Search Categories” field allows you to narrow your search for a category as you type – this functionality is not native to WordPress but is instead borrowed from Jason Corradino’s
Searchable Categories plugin. If you would like to enable this feature for your posts
download his plugin here

Since WordPress 3.5 now supports attachment taxonomy, the work of adding a metabox to the attachment editor is happening entirely inside of WordPress. This is great, and we now have true metaboxes for taxonomy – they core team has also accepted my patches which caused several headaches for this plugin. Media Categories 1.5 takes advantage of the new Media Modal – with this plugin, you can now edit a images categories directly from the modal screen. I’ve also fixed some long standing bugs with the shortcode gallery functionality.

Updates

• Since version 1.5 : Supports the new WordPress 3.5 by adding the metabox to the new Media Modal. Also fixed bugs in the gallery shorcode behavior. All while still supporting 3.3.x – 3.4.x
• Since version 1.4 : This plugin allows for multiple metaboxes to be created for any number of taxonomies.
• Since version 1.3 : A filter has been added to allow developers to modify which taxonomy is being used. See ‘Other Notes’ > ‘Taxonomy Filter Usage’ for details
• Since version 1.2 : This plugin extends the native [gallery] shortcode of WordPress so that it has a ‘category’ parameter. See the “Shortcode Usage” under “Other Notes” for more details.

Shortcode Usage

Normal Shortcode Usage

This plugin takes advantage of the existing [gallery] shortcode for showing images by adding the 'category' parameter.
The value passed to the 'category' parameter can be either the category slug, or the term_id.

[gallery category="my-category-slug"]
OR
[gallery category="12"]

Its important to note that when passing the 'category' parameter, the [gallery] shortcode will by default ignore the current post
and simply try to include all images from the category. The syntax above will retrieve any images that are assigned
to 'my-category-slug' a.k.a term id #12, regardless of whether or not those images are attached to the current post.

To query within a post (even the current post), you’ll need to explicitly add the post id as such…

[gallery category="my-category-slug" id="43"]

This shortcode will retrieve any images attached to post #43 that are categorized as 'my-slug-category'.

Aside from this behavior, the [gallery] shortcode should behave exactly as it does by default with the built-in shortcode.
The id parameter will behave as normal when the category parameter is not invoked.
For more information on using the built-in gallery shortcode checkout the codex page.

Other Taxonomy Shortcode Usage

If a developer implementing this plugin has made use of the mc_taxonomy filter to modify which taxonomy
this plugin uses for attachments, then the name of that particular taxonomy will need to be used in place of category
as the shortcode parameter. For example, if you applied ‘Post Tags’ to your images then users should use the post_tag parameter
in the Gallery Shortcode.

[gallery post_tag="my-tag-slug"]
OR
[gallery post_tag="12"]

Read the full description on the official page →