What Defines What Category A Post Picks (if in multiple)

WordPress always use the category with lowest ID. You can use plugins such as the Hikari Category Permalink plugin to change that however.

http://wordpress.org/extend/plugins/hikari-category-permalink/

Related Posts:

  1. Using permalinks, category slugs, and tag slugs
  2. Can I show category name in url for only one of my categories?
  3. How to remove category and other tags from posts page
  4. Use category base slug in posts’ permalink
  5. How to control which category will be picked for the slug of a post?
  6. Post in Multiple Categories to stay in current category (permalink, next previous post link)
  7. Permalink Settings: optional settings doesn’t apply to editor
  8. WordPress menu that shows all posts in a certain category like w3schools
  9. Mark menu item as current-menu-item for category
  10. Should I use posts or pages in this scenario?
  11. WP_Query: Mixing category__in and tag__in together
  12. How to list recent posts in a wp nav menu?
  13. How can I hide tags on a child-category page, if that tag has not been used?
  14. How to get post with associated categories and tags names instead of ids with rest api?
  15. Un-highlight Blog Menu Item when Category Menu Item is Selected
  16. Having pages after specifying post_type post
  17. In what context should Categories and Tags be used
  18. Programmatically add posts from specific category to menu
  19. wp_list_categories() Exclude All Categories Except One
  20. Categories Listing and Highlighting current category item
  21. Rewriting blog permalinks
  22. WordPress – When visiting a `single post/ single.php` my category menu item link becomes active
  23. Remove subcategory slug from url
  24. Is there a way to categorize a list posts all at once?
  25. How to get tags when using publish_post
  26. I want to add the 10 most recent posts under a parent category on the main menu
  27. How to add class to specific navbar item when post parent category is in specific category
  28. How do you change the permalink for posts for a single category?
  29. Does having category name in permalinks affect SEO when having a post in multiple categories?
  30. How to add a ‘News’ section to specific posts in WordPress
  31. How to 301 redirect from url with post id to permalink with post name (slug)?
  32. Why do I have categories with duplicate slugs?
  33. show only one category and filter by tag
  34. Automatic Table of contents with categories and posts
  35. Set multi posts random categories and tags
  36. Point users to a specific url directory for some posts
  37. Precedence of page permalinks over woocommerce product category links?
  38. Make assigning post to a specific category equivalent to assigning it to all categories
  39. How to display subcategory articles in the category view?
  40. How can I fixe the article title problem?
  41. Where is the old post permalink slug stored?
  42. Manipulate post category after time
  43. How to get the url to tag & category base set by the user?
  44. Categories box not showing on post edit pages
  45. List only child categories a post is in, of a specific parent category
  46. Add custom field to all posts in specific category
  47. Root level category, tag, author and archive pages to work
  48. Some posts returning 404 instead of displaying post
  49. wp_list_categories link to first post of category instead of calling taxonomy template
  50. Edit menu item title from edit page/post
  51. Changing my permalink structure – will new layout conflict with existing page?
  52. Does an action fire when adding a tag via the “Tags” meta box?
  53. Display posts in alphabetical order for a particular category
  54. WordPress post tag & custom field
  55. How to automatically apply a category based on the post title?
  56. Direct link to “New post” in specific category?
  57. Disable most recent & view all (TABS) on nav-menu.php
  58. Get latest posts from WordPress site without header, menu and sidebar
  59. How can I make a post that belongs to a category or have specific tags, display different from the other single posts?
  60. Is it possible to change post id for an already added menu item in WordPress?
  61. How do I retrieve then print the currently viewed sub categories?
  62. Add multiple tags to multiple posts
  63. Related posts by category not working right
  64. How to add tags (custom taxonomy) to post class css?
  65. Listing Specific Categories from Current Post with Depth
  66. Redirect to another page using contact form 7? [closed]
  67. get_the_category listing in hierarchial order
  68. Displaying posts that belong to a specific author
  69. WordPress Menu options in the Admin: Posts for the dropdowns
  70. Custom permalink for each post
  71. Show posts on front page only
  72. Get current post’s nav menu name (term name)
  73. Post is in descendant category not working in home.php
  74. SQL Bulk Move old posts by one author to another category
  75. load more posts by category
  76. Display Related Posts by Category in Random
  77. How to show beneath posts the full category path?
  78. How do I keep raw HTML in my RSS feed and not lose my paragraph breaks?
  79. Set Default Post as Parent Child (Nested) Relation
  80. Display Current Posts Category (with the most posts)?
  81. How can I add random alphabets in wordpress permalink posts structure
  82. Only the most recent post is showing on my category page (working on localhost, not live site)
  83. Featured Images most often doesnt appear
  84. Get category slug of the Parent category of a Product
  85. WP posts using index.php instead of single.php
  86. Excluding tag Link from html tags in Post content
  87. How to make a page show posts only from specific categories without editing php files
  88. How to Get Position of a Post from a category and tag
  89. Display new posts categories in separated divs
  90. Add Categories To Custom Post
  91. Display Posts by Categories
  92. Edit Posts Page but not category specific pages?
  93. “Current” class on a singular page menu item with custom post types?
  94. Displaying different posts Via wp_list_categories()
  95. Should new posts already have tags?
  96. Show all posts in category
  97. Polylang – display one post into 3 categories with different lang [closed]
  98. Changes done in admin panel are taking time to reflect in the REST api responses
  99. Get related posts matching most of the provided tags using WP_Query
  100. I have a blog and want to prompt the user to select a category they like and have that select a random blog post