Posts and Pages

Both share the status workflow, revisions, autosaves, featured images, the author field and the trash. A custom post type such as the Lumen Press book catalogue (lp_book, registered by the lumen-catalog plugin) gets the same statuses automatically and opts into the rest through its supports list (revisions, excerpt, thumbnail, page-attributes, post-formats); see Custom Post Types and Taxonomies.

Lumen Press uses posts for its news blog ("Spring catalogue announced", "Submissions open") and pages for About, Contact and Submissions (a child of About), plus two pages, Home and News, that become the static front page and the posts page later on this page.

The status lives in the post_status column and decides who can see a post and where it is listed. Core registers twelve statuses in create_initial_post_types(); six of them are the editorial workflow, the rest are internal.

Password protected is not a status. It is a published post with a value in post_password: the title gets a "Protected:" prefix and the content is replaced by a password form until the visitor enters it. The password is stored in plain text and the cookie (wp-postpass_<hash>) lasts ten days. It is a convenience for sharing proofs with a few reviewers, not access control; anything confidential belongs behind a login (private, or a membership plugin).

The flags of each registered status (get_post_stati( array(), 'objects' )) explain the behaviour: publish is public, future, draft and pending are protected, private is private, and the rest are internal (trash is internal but still has a Trash filter in the list screens). public statuses are shown to everyone, protected ones only to users who can edit the post, private ones to users with the read_private_* capability. The REST API mirrors this: GET /wp/v2/statuses returns the five workflow statuses plus trash to an administrator and only publish to an anonymous visitor, and /wp/v2/posts?status=draft without authentication returns 400.

In the block editor the document settings sidebar (the Post or Page tab, named after the post type) holds the summary of everything on this page:

The Posts and Pages screens (edit.php, edit.php?post_type=page) list everything with filters per status (All, Mine, Published, Scheduled, Drafts, Pending, Private, Trash), and Quick Edit changes the status, date, password, parent, order, template and sticky flag without opening the editor.

A scheduled post is a post with status future and a post_date in the future. Saving it schedules a single WP-Cron event, publish_future_post, at the post’s GMT date; when it fires, check_and_publish_future_post() checks the date again and calls wp_publish_post().

Source: WP-CLI: wp cron event list

Facts that follow from this design:

Source: Code Reference: check_and_publish_future_post()

The function publishes only posts whose date has passed; for a post still in the future it re-schedules the event, so it is safe to run on every future post.

A sticky post is kept at the top of the blog index. Stickiness is not a column: the IDs are stored in the sticky_posts option, an array, and stick_post(), unstick_post() and is_sticky() manage it. Only posts can be sticky.

Source: Code Reference: stick_post()

WP_Query moves sticky posts to the top only on the posts page (is_home()), only on its first page, and only when ignore_sticky_posts is false. Sticky posts that would not be on the first page anyway are fetched and prepended, so that page can show more than "Number of recent posts shown on archive pages" posts. Category archives, search and custom queries ignore stickiness unless they ask for it. In block themes, the Query Loop block has a Sticky posts setting (include, exclude or only), which is the way to build a "featured news" strip. Classic themes style them through the sticky class added by post_class().

An excerpt is a short summary used in archives, search results, feeds (when Settings > Reading is set to show an excerpt), social previews by SEO plugins, and the Post Excerpt block. It is either written by hand in the Excerpt panel (post_excerpt column) or generated: get_the_excerpt() falls back to the first 55 words of the content with blocks, shortcodes and tags removed, followed by […].

Source: Code Reference: excerpt_length

The two filters change only generated excerpts; a hand-written excerpt is returned as is. Block themes usually set the length on the Post Excerpt block instead (excerptLength, and a "more" text). Pages have no excerpt field until a plugin adds excerpt support, as the editorial plugin below does. Excerpts are not the same as the More block (<!--more-->), which cuts the full content on index pages of classic themes and has no effect on single views.

A featured image (historically "post thumbnail") is an attachment whose ID is stored in the _thumbnail_id meta of the post. Themes display it in templates (the Post Featured Image block, or the_post_thumbnail()), and it is the default image in social previews and the REST API’s featured_media. Block themes get post-thumbnails support automatically since 5.9; classic themes must declare it. Custom post types also need thumbnail in supports.

Source: WP-CLI: wp media import

The generated <img> already has srcset, sizes="auto" (6.7), decoding="async" and loading="lazy". The alt text belongs to the attachment, not to the post, so the same cover has the same alt text everywhere it is used; write it in the Media Library (see Media Library). Deleting the image from the Media Library leaves a dangling _thumbnail_id, which themes simply skip.

Post formats (3.1+) are a fixed vocabulary a theme can use to style posts differently: aside, gallery, link, image, quote, status, video, audio and chat, plus standard meaning none. They are stored as terms of the hidden post_format taxonomy (post-format-quote), and the selector appears in the editor only when the theme declares support. Twenty Twenty-Five declares all nine; the block-theme Query Loop can filter by format.

Source: Theme Handbook: Post Formats

Formats are a presentation hint, not a content model: they cannot be added to, a theme switch can make them invisible, and a "quote" post is still a post with blocks. For real structured content such as a book with an ISBN, a custom post type with metadata is the right tool. Lumen Press uses only aside, quote and link in its classic theme (see the end of the next section).

Hierarchical post types have page attributes: post_parent (the Parent field) and menu_order (the Order field, an integer used by page lists and wp_list_pages(), not by Navigation blocks). The parent builds the URL path. Deleting a parent permanently moves its children up to the grandparent; trashing it leaves them where they are.

Source: WP-CLI: wp post create

With plain permalinks the same page is /?page_id=<id>; see Rewrite API and Permalinks.

A template chosen for a single post or page is stored in the _wp_page_template meta (default or absent means the template hierarchy decides). The list of choices comes from the active theme, so a theme switch can leave a value that no longer exists; WordPress then falls back to the hierarchy, and WP-CLI refuses an unknown value with "Invalid page template".

By default the home page lists the latest posts. Settings > Reading > Your homepage displays switches to A static page, with two drop-downs: Homepage and Posts page. Three options hold the choice:

Lumen Press shows its Home page at / and the news blog at /news/:

Source: WP-CLI: wp option update

The Home page is then served at http://lumenpress.test/ and the posts at http://lumenpress.test/news/. How the two pages are rendered surprises many site owners:

In the Site Editor of a block theme the same choice is also available from the Pages list ("Set as homepage" and "Set as posts page" actions).

Deleting a post, page, attachment or comment in the admin moves it to the trash. wp_trash_post() sets the status to trash and stores what is needed to restore it in meta: _wp_trash_meta_status (the previous status), _wp_trash_meta_time (a Unix timestamp) and _wp_desired_post_slug. The slug gets a __trashed suffix so that a new post can reuse it.

Source: WP-CLI: wp post delete

Restoring. Since 5.6, wp_untrash_post() restores a post as a draft, not with its previous status, so that a restored post is not republished by accident. The wp_untrash_post_status filter changes that, and core ships a ready-made callback, wp_untrash_post_set_previous_status(), used in the plugin below. Attachments are the exception: they always go back to inherit.

Emptying. wp_scheduled_delete() runs daily from WP-Cron and permanently deletes posts and comments whose _wp_trash_meta_time is older than EMPTY_TRASH_DAYS (default 30). The event is scheduled the first time someone loads the admin, so a site managed only by WP-CLI has no such event until then. Empty Trash on the Trash view, and Delete Permanently per item, delete immediately.

Source: Advanced Administration Handbook: wp-config.php

With EMPTY_TRASH_DAYS set to 0, the admin replaces "Trash" links with "Delete Permanently" and asks for no confirmation, and even wp post delete without --force deletes the post for good (WP-CLI still prints "Trashed", but the post is gone). Keep a positive value and rely on backups for anything older; see Backups and Disaster Recovery. Core defines these constants (in wp-includes/default-constants.php) only when wp-config.php has not, so they must be set there, not in a plugin. They can be written with wp config set EMPTY_TRASH_DAYS 7 --raw. The complete list of constants is in wp-config.php Reference.

Every save of a post whose type supports revisions (posts and pages do) copies the previous title, content and excerpt into a child post of type revision, status inherit, named <parent-id>-revision-v1. Autosaves are different: one per user per post, named <parent-id>-autosave-v1, overwritten every AUTOSAVE_INTERVAL seconds while editing and offered for recovery when the editor reopens. The editor’s revisions screen compares any two revisions and restores one; 7.0 also shows revisions as a timeline in the editor, covered in Block Editor for Authors.

WP_POST_REVISIONS limits how many are kept:

The limit is applied at save time, per post. Six updates of a post with the default setting left seven revisions; after setting WP_POST_REVISIONS to 3, the next save trimmed them to three:

Source: Code Reference: wp_revisions_to_keep()

Two filters override the constant: wp_revisions_to_keep (all types) and wp_{$post_type}_revisions_to_keep (one type, 5.8+, which also overrides the general filter). A filter wins over the constant, which is why wp_revisions_enabled() can be true even with WP_POST_REVISIONS set to false. Revisions are full copies, so an old, much-edited site can hold many times more revision rows than posts; deleting them is safe:

Source: WP-CLI: wp post list

Revisions do not store post meta by default. Plugin developers can opt registered meta into revisions with revisions_enabled in register_post_meta() (6.4+), which lumen-catalog uses for lp_isbn; see Metadata and Custom Fields.

The rules above are site policy, so Lumen Press puts them in a must-use plugin (wp-content/mu-plugins/, loaded automatically and impossible to deactivate from the admin) rather than in a theme:

Source: Code Reference: wp_untrash_post_status, Code Reference: transition_post_status

With the plugin in place and WP_DEBUG_LOG on, publishing a post, wp post delete and wp_untrash_post() leave it publish again, and wp-content/debug.log shows the transitions:

Restoring to the previous status is a policy choice: it is convenient for an editorial team that trashes by mistake, but it republishes immediately, so sites that want a second look keep the default. debug.log must not stay publicly readable in production; see Debugging, Site Health and Troubleshooting.

Block Editor for Authors, Categories, Tags and Comments, Media Library, Settings Screens, Database Schema (the wp_posts table), Template Hierarchy, WP_Query and the Database API, WP-CLI and REST API: Using It.