MediaWiki:Apihelp-readinglists+createentry-extended-description/en
List entries must be unique. Pages are not limited to the wiki where the API is accessed. The user must have fewer than $1 (non-deleted) entries in the list.
List entries must be unique. Pages are not limited to the wiki where the API is accessed. The user must have fewer than $1 (non-deleted) entries in the list.