Title: Version 3.0
Published: May 19, 2019

---

# Version 3.0

## In this article

 * [Highlights](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#highlights)
 * [User Features](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#user-features)
    - [General](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#general)
    - [Dashboard](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#dashboard)
    - [Posts](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#posts)
    - [Media](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#media)
    - [Links](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#links)
    - [Comments](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#comments)
    - [Appearance](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#appearance)
    - [Plugins](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#plugins)
    - [Tools](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#tools)
    - [Users](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#users)
    - [Settings](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#settings)
    - [Install Process](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#install-process)
    - [Multisite](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#multisite)
 * [Development, Themes, Plugins](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#development-themes-plugins)
 * [Features Deferred to Later Versions](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#features-deferred-to-later-versions)

[ Back to top](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#wp--skip-link--target)

On June 17, 2010, WordPress **Version 3.0**, named for Thelonious, was released 
to the public. For more information on this enhancement and bug-fix release, read
the [WordPress Blog](https://wordpress.org/development) and see the [Changelog for 3.0](https://codex.wordpress.org/Changelog/3.0).

For **Version 3.0**, the database version (**db_version** in **wp_options**) changed
to 15260, and the [Trac](https://core.trac.wordpress.org/) revision was 15274.

 * [View Closed Tickets](https://trac.wordpress.org/query?status=closed&milestone=3.0)

## 󠀁[Highlights](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#highlights)󠁿

 * **WordPress and WordPress MU have merged** – allowing the management of multiple
   sites (called Multisite) from one WordPress installation.
 * **New default theme [“Twenty Ten”](https://codex.wordpress.org/Glossary#Twenty_Ten_theme)**–
   takes full advantage of the current features of WordPress.
 * **New [Custom Menu](https://codex.wordpress.org/Appearance_Menus_SubPanel) Management
   feature** – allows creation of custom menus combining posts, pages, categories,
   tags, and links for use in theme menus or widgets.
 * [Custom Header](https://codex.wordpress.org/Appearance_Header_SubPanel) and [Custom Background](https://codex.wordpress.org/Appearance_Background_SubPanel)
   APIs.
 * **Contextual help** – help text accessed under the Help tab of every screen in
   the WordPress administration.
 * Ability to set the admin username and password during installation.
 * **Bulk updating of themes** – with an automatic maintenance mode during the process.
 * **Support for [Shortlinks](https://codex.wordpress.org/index.php?title=Shortlinks&action=edit&redlink=1)**.
 * **Improved [Custom Post Types](https://codex.wordpress.org/Custom_Post_Types)
   and [Custom Taxonomies](https://codex.wordpress.org/Custom_Taxonomies)** – including
   hierarchical (category-style) support. (Try the [Custom Post Type UI](https://wordpress.org/extend/plugins/custom-post-type-ui/)
   or [GD Custom Posts And Taxonomies Tools](https://wordpress.org/extend/plugins/gd-taxonomies-tools/)
   plugins to see the possibilities.)
 * **A lighter admin color scheme** – to increase accessibility and put the focus
   more squarely on your content.

## 󠀁[User Features](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#user-features)󠁿

### 󠀁[General](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#general)󠁿

 * Check required php and mysql versions in the update and notify if the server 
   environment does not meet those requirements
 * New [wp_login_form()](https://codex.wordpress.org/Function_Reference/wp_login_form)
   provides a simple login form for use anywhere
 * New WordPress logo for admin header
 * Place “Search Engines Blocked” mini-alert in the wp-admin header to prevent people
   from accidentally delisting themselves
 * Remove ‘Turbo’ link from admin header and remove Turbo section from the [Tools](https://codex.wordpress.org/Administration_Panels#Tools)-
   >[Tools](https://codex.wordpress.org/Tools_Tools_SubPanel) panel
 * Renamed various menu items, for example Posts->Edit becomes Posts->Posts, and
   Links->Edit becomes Links->Links, and so on
 * Revised administration menu icons
 * Revised Gray Admin Color Scheme
 * Revised information in `[readme.html](https://core.trac.wordpress.org/browser/tags/5.1.0/src/readme.html#L0)`
   file
 * Show login form upon email-sent for recover/reset passwords

### 󠀁[Dashboard](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#dashboard)󠁿

 * Add link so user can visit Dashboard after core upgrade
 * Move **Tools->Upgrade** menu option to **Dashboard->Updates** and overhaul of
   user interface so themes, plugins, and core upgrades under one panel
 * New menu management (navigation) via [Menus](https://codex.wordpress.org/Appearance_Menus_SubPanel)
   option under Appearances Menu ([#11817](https://core.trac.wordpress.org/ticket/11817))
 * Password nag for newly registered users
 * Split [Right Now](https://codex.wordpress.org/Dashboard_SubPanel) widget into
   Content | Discussion

### 󠀁[Posts](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#posts)󠁿

 * Allow for removing all tags in quick edit
 * Allow themes to style the visual editor with editor-style.css file, using [add_editor_style()](https://codex.wordpress.org/Function_Reference/add_editor_style)
   function
 * Enable [custom taxonomy](https://codex.wordpress.org/Custom_Taxonomies) UI for
   pages as well as for posts
 * Improved revision comparison user interface
 * Shortlinks enabled, but still requires a plugin or theme support to fully realize
   this feature
 * Added [capital_P_dangit()](https://codex.wordpress.org/Function_Reference/capital_P_dangit)
   filter to change ‘WordPress’ to ‘WordPress’.

### 󠀁[Media](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#media)󠁿

 * Add FunnyOrDie.com [oEmbed](https://codex.wordpress.org/Embeds) support
 * Allow Deletion of Media Alt text
 * Change Media UI labels from “[Post Thumbnails](https://codex.wordpress.org/Post_Thumbnails)”
   to “Featured Image”
 * Cleanup of the [edit media](https://codex.wordpress.org/Media_Library_SubPanel#Edit_Media)
   screen
 * Don’t let “Crunching” overlap image name while uploading
 * Optimize scan for lost attachments
 * Support for additional file type extensions ([Changesets 12581](https://core.trac.wordpress.org/changeset/12581)
   and [13349](https://core.trac.wordpress.org/changeset/13349))

### 󠀁[Links](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#links)󠁿

 * Order link categories by name, not count, on Add New/Edit Link page

### 󠀁[Comments](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#comments)󠁿

 * Add additional columns to the Posts Comments view
 * Allow configuration of number of comments to display Recent Comments [dashboard](https://codex.wordpress.org/Dashboard_SubPanel)
   module
 * Block comments for future posts and password protected posts (when password not
   provided)
 * Change to comments UI to show when a comment is replying to another, and link
   to the parent comment

### 󠀁[Appearance](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#appearance)󠁿

 * Add meta_value_num and meta_key ordering for [WP_Query](https://codex.wordpress.org/Class_Reference/WP_Query)
   to allow natural numeric ordering of results
 * Add filter to [get_avatar()](https://codex.wordpress.org/Function_Reference/get_avatar)
   to allow avatars for custom comment types
 * Allow Tab indenting, Shift-Tab (outdenting), and multi-line tabbing, in [theme](https://codex.wordpress.org/Appearance_Editor_SubPanel)
   editor
 * Allow the [Tag Cloud Widget](https://codex.wordpress.org/Appearance_Widgets_SubPanel)
   to support non-tag taxonomies
 * Allow theme background customization via new [Background](https://codex.wordpress.org/Appearance_Background_SubPanel)
   panel under Appearance menu
 * New template file, [_front-page.php_](https://codex.wordpress.org/Template_Hierarchy#Front_Page_display),
   for the front page of a site
 * New template file, [_single-{post\_type}.php_](https://codex.wordpress.org/Template_Hierarchy#Single_Post_display),
   for [Custom Post Types](https://codex.wordpress.org/Custom_Post_Types)
 * New template files, [_author-{nicename}.php_](https://codex.wordpress.org/Template_Hierarchy#Author_display),
   and [_author-{id}.php_](https://codex.wordpress.org/Template_Hierarchy#Author_display),
   for author specific templates
 * New template files, [taxonomy.php](https://codex.wordpress.org/Template_Hierarchy#Custom_Taxonomies_display),
   [taxonomy-{taxonomy}.php](https://codex.wordpress.org/Template_Hierarchy#Custom_Taxonomies_display)
   and [taxonomy-{taxonomy}-{term}.php](https://codex.wordpress.org/Template_Hierarchy#Custom_Taxonomies_display)
   for [Custom Taxonomies](https://codex.wordpress.org/Custom_Taxonomies)
 * Style tweaks to [theme editor](https://codex.wordpress.org/Appearance_Editor_SubPanel)
 * Tab interface for Manage Themes and Install Themes in [Appearance](https://codex.wordpress.org/Administration_Panels#Appearance)-
   >[Themes](https://codex.wordpress.org/Appearance_Themes_SubPanel) panel
 * Improved child theme support; child theme use is highly encouraged and as described
   in the [Child Themes](https://codex.wordpress.org/Child_Themes) article, very
   simple to accomplish
 * New [comment_form()](https://codex.wordpress.org/Template_Tags/comment_form) 
   that outputs a complete commenting form for use within a theme template
 * The [Default](https://wordpress.org/extend/themes/default) (Kubrick), and [Classic](https://wordpress.org/extend/themes/classic)
   themes, are no longer included in the WordPress distribution, but are available
   in the Theme repository

### 󠀁[Plugins](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#plugins)󠁿

 * Add Details and Install Now action links under each plugin listed in Install 
   Plugins
 * Allow Tab indenting, Shift-Tab (outdenting), and multi-line tabbing, in [plugin](https://codex.wordpress.org/Plugins_Editor_SubPanel)
   editor
 * Upgrade plugins in bulk from the [Plugins](https://codex.wordpress.org/Administration_Panels#Plugins)-
   >[Installed](https://codex.wordpress.org/Plugins_Installed_SubPanel) panel ([#11542](https://core.trac.wordpress.org/ticket/11542))
 * When deleting plugins, check for uninstall hooks, and warn of data deletion

### 󠀁[Tools](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#tools)󠁿

 * Add tag-to-category and category-to-tag converters to [the Tools](https://codex.wordpress.org/Tools_Tools_SubPanel)
   panel, add tag-to-category converter links to [Posts](https://codex.wordpress.org/Administration_Panels#Posts)-
   >[Post Tags](https://codex.wordpress.org/Posts_Tags_SubPanel)panel
 * Clean up OPML link export script
 * Expanded filter criteria in [Tools](https://codex.wordpress.org/Administration_Panels#Export)-
   >[Export](https://codex.wordpress.org/Tools_Export_SubPanel) panel
 * [Import WordPress](https://codex.wordpress.org/Tools_Import_SubPanel) fixes notices,
   attachments, and users
 * Removed Turbo menu item, but because Turbo files weren’t removed, Turbo may still
   work
 * All importers moved to the plugin repository (e.g. [WordPress Importer](https://wordpress.org/extend/plugins/wordpress-importer/))

### 󠀁[Users](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#users)󠁿

 * Allow “No role for this blog” to be chosen in [Users](https://codex.wordpress.org/Administration_Panels#Users)-
   >[Add New](https://codex.wordpress.org/Users_Add_New_SubPanel) panel
 * Added update_core, list_users, remove_users, add_users, promote_users, edit_theme_options,
   delete_themesand export [Capabilities](https://codex.wordpress.org/Roles_and_Capabilities)

### 󠀁[Settings](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#settings)󠁿

 * Removed [Settings](https://codex.wordpress.org/Administration_Panels#Settings)-
   >[Miscellaneous](https://codex.wordpress.org/Settings_Miscellaneous_SubPanel)
   admin menu, moved uploads settings to [Settings](https://codex.wordpress.org/Administration_Panels#Settings)-
   >[Media](https://codex.wordpress.org/Settings_Media_SubPanel) panel
 * Revise [Settings](https://codex.wordpress.org/Administration_Panels#Settings)-
   >[General](https://codex.wordpress.org/Settings_General_SubPanel) panel, change“
   Blog” reference to “Site”
 * Revise Gray Admin Color Scheme

### 󠀁[Install Process](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#install-process)󠁿

 * Choose username and password during [installation](https://codex.wordpress.org/Installing_WordPress)
   rather than using ‘admin’
 * Show “Log In” button on install.php when “Already Installed”
 * Automatic generation of [Security Keys](https://codex.wordpress.org/Editing_wp-config.php#Security_Keys)
   during installation
 * Validate [_table\_prefix_](https://codex.wordpress.org/Editing_wp-config.php#table_prefix)
   in [_wp-config.php_](https://codex.wordpress.org/Editing_wp-config.php) generator
 * Standardize information in `[wp-config-sample.php](https://core.trac.wordpress.org/browser/tags/5.1.0/src/wp-config-sample.php#L0)`

### 󠀁[Multisite](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#multisite)󠁿

 * New [Tools](https://codex.wordpress.org/Administration_Panels#Tools)->[Network](https://codex.wordpress.org/Tools_Network_SubPanel)
   panel to ‘install’ mulitsite/network ability, and is available only if **WP_ALLOW_MULTISITE**
   is defined in [_wp-config.php_](https://codex.wordpress.org/Editing_wp-config.php)
 * New [Super Admin](https://codex.wordpress.org/Administration_Panels#Super_Admin)
   menu with [Admin](https://codex.wordpress.org/Super_Admin_Admin_SubPanel), [Sites](https://codex.wordpress.org/Super_Admin_Sites_SubPanel),
   [Users](https://codex.wordpress.org/Super_Admin_Users_SubPanel), [Themes](https://codex.wordpress.org/Super_Admin_Themes_SubPanel),
   [Options](https://codex.wordpress.org/Super_Admin_Options_SubPanel), [Update](https://codex.wordpress.org/Super_Admin_Update_SubPanel),
   sub-menus (available only if [is_multisite()](https://codex.wordpress.org/Function_Reference/is_multisite)&&
   [is_super_admin()](https://codex.wordpress.org/Function_Reference/is_super_admin))
 * New [Dashboard](https://codex.wordpress.org/Administration_Panels#Dashboard)-
   >[My Sites](https://codex.wordpress.org/Dashboard_My_Sites_SubPanel) panel
 * New [Tools](https://codex.wordpress.org/Administration_Panels#Tools)->[Delete Site](https://codex.wordpress.org/index.php?title=Tools_Delete_Site_SubPanel&action=edit&redlink=1)
   panel
 * [Configure a Network](https://codex.wordpress.org/Create_A_Network) (multisite/
   WPMU) using [_wp-config.php_](https://codex.wordpress.org/Editing_wp-config.php)
   file
 * Terminology changes regarding Sites, Blogs, Networks (see [Andrew Nacin’s explanation](http://www.andrewnacin.com/2010/03/25/terminology-nightmare-blogs-sites-networks/))

## 󠀁[Development, Themes, Plugins](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#development-themes-plugins)󠁿

 * A better default excerpt; remove multiple white spaces from the excerpt as well
   as splitting safely on UTF8 strings

 * Add [Child theme](https://codex.wordpress.org/Child_Themes) support for theme
   header registrations, second call to [register_theme_headers()](https://codex.wordpress.org/index.php?title=Function_Reference/register_theme_headers&action=edit&redlink=1)
   should add more headers, and not replace existing headers.
 * Add [add_plugins_page()](https://codex.wordpress.org/Function_Reference/add_plugins_page)
   function to allow adding a submenu to under Plugins menu
 * Add [get_search_link()](https://codex.wordpress.org/Function_Reference/get_search_link)
   with Permastruct (/search/) support, update [get_search_link()](https://codex.wordpress.org/Function_Reference/get_search_link),
   [get_search_feed_link()](https://codex.wordpress.org/Function_Reference/get_search_feed_link)
   and [get_search_comments_feed_link()](https://codex.wordpress.org/Function_Reference/get_search_comments_feed_link)
 * Add [is_comment_feed()](https://codex.wordpress.org/Function_Reference/is_comment_feed)
 * Add [redirect_to](https://codex.wordpress.org/index.php?title=Plugin_API/Filter_Reference/redirect_to&action=edit&redlink=1)
   and [associated](https://codex.wordpress.org/index.php?title=Plugin_API/Filter_Reference/associated&action=edit&redlink=1)
   filters to registration and password recovery
 * Add a [wp_loaded](https://codex.wordpress.org/Plugin_API/Action_Reference/wp_loaded)
   action that fires once WordPress init has finished
 * Add an INDEX on comment_parent ([wp_comments](https://codex.wordpress.org/Database_Description#Table:_wp_comments)
   table) to speed up wp_delete_comment() and reparenting queries
 * Add argument _hide\_if\_empty_ to [wp_dropdown_categories()](https://codex.wordpress.org/Template_Tags/wp_dropdown_categories)
   to hide dropdown if no terms to display
 * Add argument _id_ to [wp_dropdown_users()](https://codex.wordpress.org/Template_Tags/wp_dropdown_users)
   and [wp_dropdown_categories()](https://codex.wordpress.org/Template_Tags/wp_dropdown_categories)
 * Add argument _post\_type_ to [get_page_by_title()](https://codex.wordpress.org/Function_Reference/get_page_by_title)
 * Add argument _taxonomies_ to [register_post_type()](https://codex.wordpress.org/Function_Reference/register_post_type)
 * Add argument _taxonomy_ to [wp_list_categories()](https://codex.wordpress.org/Template_Tags/wp_list_categories)
   and [wp_dropdown_categories()](https://codex.wordpress.org/Template_Tags/wp_dropdown_categories)
   to be custom taxonomy aware
 * Add capability ‘edit_theme_options’ (see [developer discussion on this](http://wpdevel.wordpress.com/2010/04/16/i-notice-a-lot-of-themes-passing-the-e/))
 * Add capability ‘list_users’ to provide more controls over listing users vs. editing
   users
 * Add compatibility code for old themes that relied on templates from the default
   theme without expressly identifying it as the parent theme (Note: the fallback
   to these template files is now deprecated and will be removed in a future version)
 * Add custom hierarchical post type support to [get_pages()](https://codex.wordpress.org/Function_Reference/get_pages)
 * Add defaults for ‘post_content’ and ‘post_title’ in [wp_insert_post()](https://codex.wordpress.org/Function_Reference/wp_insert_post)
 * Add email and login duplicate checking to [wp_insert_user()](https://codex.wordpress.org/Function_Reference/wp_insert_user)
 * Add extra hooks to “Right Now” dashboard widget
 * Add filter to the links in [paginate_links()](https://codex.wordpress.org/Template_Tags/paginate_links)
   and to the arguments in [wp_link_pages()](https://codex.wordpress.org/Template_Tags/wp_link_pages)
 * Add filter post_updated_messages to allow changes to the $messages array in wp-
   admin/edit-form-advanced.php
 * Add filter post_updated action fires when a post is updated; post ID, current
   and previous post objects are passed and wp_check_for_changed_slugs() updated
   to use new hook
 * Add flag to taxonomy registration allowing permalinks to be prepended with front,
   or not
 * Add initial **WP_DEBUG** define to [_wp-config-sample.php_](https://codex.wordpress.org/Editing_wp-config.php)
   and suggest plugin/theme developers use it
 * Add mobile webkit styles for twentyten theme
 * Add more orderby and select options to [get_comments](https://codex.wordpress.org/Function_Reference/get_comments)
 * Add Multisite capabilities ([#11644](https://core.trac.wordpress.org/ticket/11644))
 * Add new protocols for kses and make the list of protocols filterable
 * Add optional comment ID argument to comment template functions
 * Add replace method to [$wpdb](https://codex.wordpress.org/Function_Reference/wpdb_Class)(
   [#10864](https://core.trac.wordpress.org/ticket/10864))
 * Add support to [get_terms()](https://codex.wordpress.org/Function_Reference/get_terms)
   to allow ‘include’ & ‘exclude’ args to be arrays()
 * Add support to [is_singular()](https://codex.wordpress.org/Conditional_Tags#A_Single_Page.2C_Single_Post_or_Attachment)
   to allow testing of specific post_types such as is_singular(‘book’) or is_singular(
   array( ‘newspaper’, ‘book’ ) )
 * Add the generator element in feeds through the {rss2|atom|rdf|rss|opml}_head 
   hooks
 * Add ‘themes_loaded’ hook to run after parent/child themes have been included
 * Add ?ver=DATE query strings to all images that changed since 2.9, to expire browser
   cache and bump versions on all CSS/JS files modified in that process
 * Admin support for [Custom Post Types](https://codex.wordpress.org/Custom_Post_Types)(
   [#9674](https://core.trac.wordpress.org/ticket/9674))
 * Admin support for hierarchical taxonomies ([#10122](https://core.trac.wordpress.org/ticket/10122))
 * Allow [Custom Post Types](https://codex.wordpress.org/Custom_Post_Types) to have
   custom icons
 * Allow enabling/disabling title and editor per post type, introduce [remove_post_type_support()](https://codex.wordpress.org/Function_Reference/remove_post_type_support),
   add enable/disable for author override
 * Allow include/exclude arguments for [get_posts()](https://codex.wordpress.org/Template_Tags/get_posts)
   and [get_pages()](https://codex.wordpress.org/Function_Reference/get_pages) to
   be an array
 * Allow methods to be used as a callback in [wp_unique_filename()](https://codex.wordpress.org/Function_Reference/wp_unique_filename)
 * Allow more special characters in [wp_generate_password()](https://codex.wordpress.org/Function_Reference/wp_generate_password)
 * Allow multiple To: recipients in [wp_mail()](https://codex.wordpress.org/Function_Reference/wp_mail)
   and improve handling of \r\n in headers and multiple CC/BCC headers
 * Allow people to attach PHP 5.3 Closures to filters and actions
 * Allow plugins to modify the query run by WP_User_Search
 * Allow themes to specify a menu fallback other than [wp_page_menu()](https://codex.wordpress.org/Template_Tags/wp_page_menu)
 * Better inline documentation for **WP_DEBUG**, **WP_DEBUG_DISPLAY**, and **WP_DEBUG_LOG**.
 * Better POST_BY_EMAIL logic
 * Check PHP and MySQL versions in upgrade.php
 * Convert Terms page to use WP_Ajax_Response(), hierarchical terms will now appear
   under their parent OR have the parents prefixed ([Changeset 13086](https://core.trac.wordpress.org/changeset/13086))
 * Create metaboxes for hierarchical taxonomies
 * Create post_status=auto-draft when creating a new post item and status changes
   to draft on first auto-save
 * Customizable death ([wp_die()](https://codex.wordpress.org/Function_Reference/wp_die)
   is now pluggable) ([#11892](https://core.trac.wordpress.org/ticket/11892))
 * [Deprecate](https://codex.wordpress.org/Glossary#Deprecated) [get_alloptions()](https://codex.wordpress.org/Function_Reference/get_alloptions)
 * Deprecate [get_profile()](https://codex.wordpress.org/Function_Reference/get_profile)
   for [get_the_author_meta()](https://codex.wordpress.org/index.php?title=Template_Tags/get_the_author_meta&action=edit&redlink=1)
 * Deprecate [trackback_rdf()](https://codex.wordpress.org/Function_Reference/trackback_rdf)(
   [#11139](https://core.trac.wordpress.org/ticket/11139))
 * Deprecate add_option_update_handler() and remove_option_update_handler() in favor
   of [register_setting()](https://codex.wordpress.org/Function_Reference/register_setting)
   and [unregister_setting()](https://codex.wordpress.org/Function_Reference/unregister_setting)
 * Deprecate automatic_feed_links() in favor of [add_theme_support](https://codex.wordpress.org/Function_Reference/add_theme_support)(‘
   automatic-feed-links’)
 * Deprecate get_bloginfo(‘text_direction’) in favor of [is_rtl()](https://codex.wordpress.org/Function_Reference/is_rtl)
 * Deprecate [set_current_user()](https://codex.wordpress.org/Function_Reference/set_current_user)
   in favor of [wp_set_current_user()](https://codex.wordpress.org/Function_Reference/wp_set_current_user)
 * Deprecate MagpieRSS in favor of Simplepie ([#11982](https://core.trac.wordpress.org/ticket/11982))
 * Deprecate Snoopy
 * Deprecate [User Levels](https://codex.wordpress.org/User_Levels) (use [Roles and Capabilities](https://codex.wordpress.org/Roles_and_Capabilities)
   instead) ([#10805](https://core.trac.wordpress.org/ticket/10805))
 * Deprecate [clean_url()](https://codex.wordpress.org/Function_Reference/clean_url)
   in favor of [esc_url() and esc_url_raw()](https://codex.wordpress.org/Data_Validation)(
   [#12309](https://core.trac.wordpress.org/ticket/12309))
 * Deprecate **VHOST** in favor of a boolean, **SUBDOMAIN_INSTALL** (Note: core 
   will keep VHOST defined for plugins’ sake, but you should only define SUBDOMAIN_INSTALL;
   will throw notice if VHOST is defined, and a warning if they somehow conflict;
   sunrise can still handle them
 * Deprecate is_term and is_taxonomy in favor of term_exists and taxonomy_exists
 * Don’t check for the existence of index.php in the htaccess rewrite rules
 * Don’t query against entire users table in [wp_dropdown_users()](https://codex.wordpress.org/Template_Tags/wp_dropdown_users)
 * Don’t require a default category for post types other than ‘post’
 * Ensure that for multiple sidebar additions, the ID is unique
 * Extend [the_modified_date()](https://codex.wordpress.org/Template_Tags/the_modified_date)
   to support before/after/echo
 * Fallback to [wp_page_menu()](https://codex.wordpress.org/Template_Tags/wp_page_menu)
   from [wp_nav_menu()](https://codex.wordpress.org/Template_Tags/wp_nav_menu) if
   no menus are setup
 * Fix [Press This](https://codex.wordpress.org/Press_This) entity encoding
 * Fix DST/Standard transition display in [Settings](https://codex.wordpress.org/Administration_Panels#Settings)-
   >[General](https://codex.wordpress.org/Settings_General_SubPanel)
 * Fix recursive chmod for WP_Filesystem
 * Flag post statuses as public, private, protected, or internal
 * Functon [get_usernumposts()](https://codex.wordpress.org/Function_Reference/get_usernumposts)
   is now deprecated in favor of [count_user_posts()](https://codex.wordpress.org/Function_Reference/count_user_posts)
   for naming consistency
 * Improve user listing performance
 * In Twenty Ten theme, don’t use [post thumbnail](https://codex.wordpress.org/Post_Thumbnails)
   as the [custom header](https://codex.wordpress.org/Appearance_Header_SubPanel)
   if it’s smaller than the header size
 * Introduce *_user_meta() functions, deprecate *_usermeta() family
 * Introduce _ex(), a hybrid between _e() and _x(), to translate with context, then
   echo.
 * Introduce [add_editor_style()](https://codex.wordpress.org/Function_Reference/add_editor_style)
   to easily register a stylesheet for the visual editor
 * Introduce [add_permastruct()](https://codex.wordpress.org/Function_Reference/add_permastruct)
   and [flush_rewrite_rules()](https://codex.wordpress.org/Function_Reference/flush_rewrite_rules),
   wrappers for the corresponding WP_Rewrite methods
 * Introduce [disabled()](https://codex.wordpress.org/Function_Reference/disabled)
   form helper, move [selected()](https://codex.wordpress.org/Function_Reference/selected)
   and [checked()](https://codex.wordpress.org/Function_Reference/checked) out of
   wp-admin and into full scope
 * Introduce [delete_user_option()](https://codex.wordpress.org/Function_Reference/delete_user_option)
 * Introduce [get_available_languages()](https://codex.wordpress.org/index.php?title=Function_Reference/get_available_languages&action=edit&redlink=1)
 * Introduce [get_comment_id_fields()](https://codex.wordpress.org/index.php?title=Function_Reference/get_comment_id_fields&action=edit&redlink=1)
   to get _comment\_id\_fields()_ and introduce a filter on the output to add extra
   fields
 * Introduce [get_index_template()](https://codex.wordpress.org/index.php?title=Function_Reference/get_index_template&action=edit&redlink=1)
   to allow [child themes](https://codex.wordpress.org/Child_Themes) to override
   a parent theme’s index.php
 * Introduce [get_intermediate_image_sizes()](https://codex.wordpress.org/Function_Reference/get_intermediate_image_sizes)
   for getting all the intermediate image sizes to be used both when adding attachements
   and deleting
 * Introduce [get_post_types()](https://codex.wordpress.org/Function_Reference/get_post_types)
   function to get a list of registered post types
 * Introduce [get_super_admins()](https://codex.wordpress.org/Function_Reference/get_super_admins)
   and allow hard-coding a global super_admins array and bypassing site options
 * Introduce [get_taxonomies()](https://codex.wordpress.org/Function_Reference/get_taxonomies)
   function to get a list of all registered taxonomies ([#12516](https://core.trac.wordpress.org/ticket/12516))
 * Introduce [get_template_part()](https://codex.wordpress.org/Function_Reference/get_template_part)
   function to [include generic files](https://codex.wordpress.org/Include_Tags)(
   other than header, sidebar, footer) ([#13146](https://core.trac.wordpress.org/changeset/13146),
   [#13816](https://core.trac.wordpress.org/changeset/13816))
 * Introduce [get_term_feed_link()](https://wordpress.org/documentation/wordpress-version/version-3-0/https_://codex.wordpress.org/index.php?title=Function_Reference/get_term_feed_link&action=edit&redlink=1)
   and use it in [wp_list_categories()](https://codex.wordpress.org/Template_Tags/wp_list_categories)
 * Introduce [get_the_author_link()](https://codex.wordpress.org/Template_Tags/get_the_author_link)
 * Introduce [get_the_date()](https://codex.wordpress.org/Template_Tags/get_the_date)
 * Introduce [home_url()](https://codex.wordpress.org/Template_Tags/home_url)
 * Introduce [is_child_theme()](https://codex.wordpress.org/Function_Reference/is_child_theme)
 * Introduce [is_post_type_hierarchical()](https://codex.wordpress.org/Conditional_Tags#A_Post_Type_is_Hierarchical)
   to use to check if a post type support hierarchical
 * Introduce [is_rtl()](https://codex.wordpress.org/Function_Reference/is_rtl) and
   becomes defined when locale is loaded
 * Introduce [is_super_admin()](https://codex.wordpress.org/Function_Reference/is_super_admin)
 * Introduce [is_textdomain_loaded()](https://codex.wordpress.org/index.php?title=Function_Reference/is_textdomain_loaded&action=edit&redlink=1)
 * Introduce [menu_page_url()](https://codex.wordpress.org/Function_Reference/menu_page_url)
   for plugins to use to get the URL for the pages they have added
 * Introduce [register_admin_color_schemes()](https://codex.wordpress.org/Function_Reference/register_admin_color_schemes)
   to registers the default admin color schemes
 * Introduce [remove_theme_support()](https://codex.wordpress.org/Function_Reference/remove_theme_support)
 * Introduce [post_type_exists()](https://codex.wordpress.org/Function_Reference/post_type_exists)
 * Introduce [sanitize_key()](https://codex.wordpress.org/Function_Reference/sanitize_key)
 * Introduce [set_current_screen()](https://codex.wordpress.org/Function_Reference/set_current_screen).
   Set current screen for inline edit ajax requests so post rows can be properly
   displayed.
 * Introduce [taxonomy_exists()](https://codex.wordpress.org/Function_Reference/taxonomy_exists)
   to replace is_taxonomy()
 * Introduce [term_exists()](https://codex.wordpress.org/Function_Reference/term_exists)
   to replace is_term()
 * Introduce [the_shortlink()](https://codex.wordpress.org/Template_Tags/the_shortlink)
   template tag ([#10640](https://core.trac.wordpress.org/ticket/10640))
 * Introduce [unload_textdomain()](https://codex.wordpress.org/Function_Reference/unload_textdomain)
   and add [plugin_locale](https://codex.wordpress.org/index.php?title=Plugin_API/Filter_Reference/plugin_locale&action=edit&redlink=1)
   and [theme_locale](https://codex.wordpress.org/index.php?title=Plugin_API/Filter_Reference/theme_locale&action=edit&redlink=1)
   filters to load_*_textdomain() functions
 * Introduce [unregister_theme_headers()](https://codex.wordpress.org/index.php?title=Function_Reference/unregister_theme_headers&action=edit&redlink=1)
 * Introduce [update_blog_details()](https://codex.wordpress.org/Function_Reference/update_blog_details)
 * Introduce [wp_check_filetype_and_ext()](https://codex.wordpress.org/Function_Reference/wp_check_filetype_and_ext)
   to handle mime/ext image comparisons and corrections for upload and sideload
 * Introduce [wp_reset_postdata()](https://codex.wordpress.org/Function_Reference/wp_reset_postdata)
   to reset the post global for the current query_posts() call after using a loop
   with a new WP_Query object
 * Introduce constant **DISALLOW_FILE_MODS** for disabling all ops that modify core,
   theme, or plugins files
 * Introduce constant **DISALLOW_FILE_EDIT** flag for enabling/disabling the theme
   and plugin editors
 * Introduce constant **DISALLOW_UNFILTERED_HTML** to disallow unfiltered_html for
   all users, even admins and super admins
 * Introduce constant **SUBDOMAIN_INSTALL** boolean to replace **VHOST**
 * Introduce constant **WP_DEFAULT_THEME** to use to set ‘default’ theme when installing
   new sites
 * Introduce Custom Taxonomies translation strings
 * Introduce theme compatibility files so incomplete themes that need to inherit
   templates will inherit them from wp-includes/theme-compat
 * Introduce WP_User::for_blog() and current_user_can_for_blog() to avoid calls 
   to WP_User::_init_caps()
 * Introduce wpdb::tables() to fetch table names on a global or blog scope
 * Introduce ZipArchive version of [unzip_file()](https://codex.wordpress.org/Function_Reference/unzip_file)(
   more efficient on memory usage for supporting hosts)
 * Make [get_bloginfo(‘wpurl’)](https://codex.wordpress.org/Template_Tags/get_bloginfo)
   use [site_url()](https://codex.wordpress.org/Template_Tags/site_url), not [get_option(‘siteurl’)](https://codex.wordpress.org/Function_Reference/get_option)
 * Make better use of $wp_query->get_queried_object()
 * Make calendar valid HTML 5
 * Merge [clear_global_post_cache()](https://codex.wordpress.org/Function_Reference/clear_global_post_cache)
   into [clean_post_cache()](https://codex.wordpress.org/Function_Reference/clean_post_cache)
 * Merge Categories/Hierarchical taxonomies into edit-tags.php
 * Merge edit-page-form.php into edit-form-advanced.php
 * Merge edit-pages.php into edit.php
 * Merge page.php into post.php
 * Merge page-new.php into post-new.php
 * More powerful version of [is_tax()](https://codex.wordpress.org/Function_Reference/is_tax)
 * Move [send_nosniff_header()](https://codex.wordpress.org/Function_Reference/send_nosniff_header)
   into wp-includes so it can be used in wp-ajax.php
 * New $required_mysql_version global in wp-db.php
 * New [comment_form()](https://codex.wordpress.org/Template_Tags/comment_form) 
   that outputs a complete commenting form for use within a template ([#10910](https://core.trac.wordpress.org/ticket/10910))
 * New [posts_search](https://codex.wordpress.org/Plugin_API/Filter_Reference/posts_search)
   filter in query.php
 * Numerous functions deprecated and changes to not use those deprecated functions
 * Optimize [single_post_title()](https://codex.wordpress.org/Template_Tags/single_post_title),
   [single_tag_title()](https://codex.wordpress.org/Template_Tags/single_tag_title)&
   [single_cat_title()](https://codex.wordpress.org/Template_Tags/single_cat_title)
   to use WP_Query globals if available
 * Pass default post to [default_content](https://codex.wordpress.org/index.php?title=Plugin_API/Filter_Reference/default_content&action=edit&redlink=1),
   [default_title](https://codex.wordpress.org/index.php?title=Plugin_API/Filter_Reference/default_title&action=edit&redlink=1),
   and [default_excerpt](https://codex.wordpress.org/index.php?title=Plugin_API/Filter_Reference/default_excerpt&action=edit&redlink=1)
   filters, to allow filtering by post_type and other attributes
 * Prevent page(\d+) slugs, and force a suffix
 * Recommended reading from a theme developer’s view regarding navigation menus;
   see [Ryan Boren’s recommendation](http://wpdevel.wordpress.com/2010/06/02/justin-has-a-nice-theme-developer-orient/)
 * Redirect ?page_id=xx for the Po sts page to the posts page
 * Refactor get_available_languages() to use glob() instead of *dir functions
 * Reminder that escaping rules for options and transients changed so see [Ryan Boren’s explanation](http://wpdevel.wordpress.com/2010/04/19/this-is-a-reminder-that-as-per-ticket-12/)
 * Reminder to plugin authors to test and make sure they do not generate unexpected
   output; see [Ryan Boren’s explanation](http://wpdevel.wordpress.com/2010/05/28/during-plugin-activation-wp-3-0-checks/)
 * Remove STYLE_DEBUG constant, SCRIPT_DEBUG now handles both scripts and CSS
 * Remove wp-ajax.php. admin-ajax.php can be used (and is better for) for front-
   end/nopriv AJAX requests
 * Rename [get_post_link()](https://codex.wordpress.org/index.php?title=Function_Reference/get_post_link&action=edit&redlink=1)
   to [get_post_permalink()](https://codex.wordpress.org/Template_Tags/get_post_permalink)
   to avoid conflict with [bbPress](https://codex.wordpress.org/bbPress)
 * Rename the new ‘themes_loaded’ hook to ‘after_setup_theme’ to prevent confusion
   as to what it actually does & where its fired from
 * Revised [Coding Standards](https://codex.wordpress.org/WordPress_Coding_Standards):
   no camelcase variables, use lowercase for variables
 * Serve a real 404 for ?p=does-not-exist, ?cat=does-not-exist, etc
 * Show custom hierarchical taxonomies in the menus
 * Show theme installer only to super admins
 * Suffix and version bump for ie.css
 * The [Settings API](https://codex.wordpress.org/Settings_API) now supports automatic
   error display for validation problems with [add_settings_error()](https://codex.wordpress.org/Function_Reference/add_settings_error)(
   [#11474](https://core.trac.wordpress.org/ticket/11474))
 * Tidy up logic for defining **WP_DEBUG**
 * Update [wp_popular_terms_checklist()](https://codex.wordpress.org/index.php?title=Function_Reference/wp_popular_terms_checklist&action=edit&redlink=1)
   to handle custom taxonomies
 * Update jQuery to 1.4.2 ([#12305](https://core.trac.wordpress.org/ticket/12305))
 * Update jQuery UI to 1.7.3
 * Update json lib
 * Update phpass to 0.2
 * Update Prototype.js to 1.6.1
 * Update Scriptaculous.js to 1.8.3
 * Update SWFobject JS to 2.2
 * Update wp_clear_scheduled_hook calls to use array when passing args
 * Use [admin_url()](https://codex.wordpress.org/Function_Reference/admin_url) for
   images in wp-admin, to allow for filtering
 * Use [get_terms()](https://codex.wordpress.org/Function_Reference/get_terms) in
   [wp_count_terms()](https://codex.wordpress.org/Function_Reference/wp_count_terms)
 * Various [phpDoc](https://codex.wordpress.org/Inline_Documentation) updates
 * Various changes to wp-includes/http.php

## 󠀁[Features Deferred to Later Versions](https://wordpress.org/documentation/wordpress-version/version-3-0/?output_format=md#features-deferred-to-later-versions)󠁿

These features didn’t make it into current release and have been designated for 
a future release.

 * Overhaul of user roles
 * Media uploader improvements

First published

May 19, 2019

Last updated