WordPress Reserved Variables

Here you find reserved names which should not be used as variable names for POST, GET requests. Also it is not recommended to use them when creating custom post types, taxonomies etc.

Such names are created or specified when registering a taxonomy or new post type. Or when creating new rewrite rules.

Before you name a post type or taxonomy or other query variable, be sure to check if your name is NOT the same as the one of the list below. If this list has such a name, you need to come up with another one.

Below is a "black list" of query variables (forbidden variables in WordPress). Don't use the values below in query variables, because they are already used in WordPress.

All query variables

attachment
attachment_id
author
author_name
calendar
cat
category_name
category__and
category__in
category__not_in
comments_per_page
comments_popup
cpage
day
debug
error
exact
feed
hour
link
minute
monthnum
more
name
nav_menu
nopaging
offset
order
orderby
p
page
paged
pagename
page_id
pb
perm
post
posts
posts_per_archive_page
posts_per_page
post_format
post_mime_type
post_status
post_type
preview
robots
s
search
second
sentence
showposts
static
subpost
subpost_id
tag
tag_id
tag_slug__and
tag_slug__in
tag__and
tag__in
tag__not_in
taxonomy
tb
term
type
w
withcomments
withoutcomments
year

Public query variables

attachment
attachment_id
author
author_name
cat
calendar
category_name
comments_popup
cpage
day
error
exact
feed
hour
m
minute
monthnum
more
name
order
orderby
p
page_id
page
paged
pagename
pb
post_type
posts
preview
robots
s
search
second
sentence
static
subpost
subpost_id
taxonomy
tag
tb
tag_id
term
tb
w
withcomments
withoutcomments
year

Internal query variables

category__in
category__not_in
category__and
comments_per_page
offset
perm
post__in
post__not_in
post_mime_type
post_parent__in
tag__and
tag__in
tag__not_in
tag_id
tag_slug__and
tag_slug__in
meta_key
meta_value