While developing WordPress theme or plugin we use different WordPress keywords or terms, additionally while handling forms fields and custom post types we have to consider what names we can use or not. The restricted names are called reserved terms.
WordPress itself reserves few keywords or terms which we can not use in our coding. Using these reserved or restricted terms just break the functionality what we intend to get.
You should avoid using these reserved terms in the following scenarios:
- Passing a term through a $_GET or $_POST array.
- Registering a taxonomy or post type slug
- Handling query variables
List of reserved keywords in alphabetical order
| attachment | attachment_id | author |
| author_name | calendar | cat |
| category | category__and | category__in |
| category__not_in | category__not_in | category_name |
| comments_per_page | comments_popup | custom |
| customize_messenger_channel | customized | cpage |
| day | debug | embed |
| error | exact | feed |
| hour | link_category | m |
| minute | monthnum | more |
| name | nav_menu | nonce |
| nopaging | offset | order |
| orderby | p | page |
| page_id | paged | pagename |
| pb | perm | post |
| post__in | post__not_in | post_format |
| post_mime_type | post_status | post_tag |
| post_type | posts | posts_per_archive_page |
| posts_per_page | preview | robots |
| s | search | second |
| sentence | showposts | static |
| subpost | subpost_id | tag |
| tag__and | tag__in | tag__not_in |
| tag_id | tag_slug__and | tag_slug__in |
| taxonomy | tb | term |
| terms | theme | title |
| type | w | withcomments |
| withoutcomments | year |