The requested page title is empty or contains only the name of a namespace.

Invalid or empty set name.

The gallery is empty.

The whitelist is empty.

The requested page title contains an invalid UTF-8 sequence.

The requested page title contains invalid characters: "$1".

The namespace contains invalid characters.

The block list is empty.

The uploaded file is empty.

The subject line is empty.

The message body is empty.

The autoblock list is empty.

The requested state is invalid.

The word "empty", as in "empty category". Appears in brackets after a name of an empty category.
{{Identical|Empty}}

The title is invalid.

Appears when the page title being requested contains the URL of the site and not just the page title

Page title of Special:LinkEdit; $1 is the name of the link (the page in the Link: namespace)

The requested page title contains an invalid colon at the beginning.

The target page title is invalid.

The target page title is invalid.

The group name can not be empty.

The requested page title was invalid. Pages in the Topic namespace are automatically created by Flow.

The chart or graph is empty due to missing data

The throttle override list is empty.

The supplementary comment on input is empty.