Manual:$wgHideUserContribLimit

{{SettingSummary
 * name=HideUserContribLimit
 * version_min=1.23.0
 * sha_introduced=8616f1b97023818b32012608746d5adcda181394
 * change_introduced=98267
 * version_deprecated=
 * section=User Access
 * range= (integer) or
 * default=1000
 * summary= The maximum number of edits a user can have and can still be hidden by users with the permission.

Details
A limit for performance reasons, to prevent a user with the user right from hiding a user with too many edits.

The limit can be disabled by setting to.

To determine this, the database field is used. See that page for more information.