This is the 16311th most frequent Russian word.
реестру
"Реестру" means "registry" or "register" in English.
Here, 'реестру' is in the dative case, referring to the registry where the document was entered.
Документ был внесён в реестру для дальнейшего рассмотрения.
The document was entered into the registry for further review.
In this example, 'реестру' is used to indicate to whom the additional data updates are necessary.
Системе реестру дополнительно требуется обновление данных.
The registry system additionally needs data updates.
Here, 'реестру' is used in the context of the recipient (registry) of the information.