OCI and surrender of documents

[gbhsmp]

Hi,
Indians do not get dual citizenship and so no voting rights.
So when an Indian gets OCI does his voters ID gets cancelled by High commision contacting the concerned authorities or that it is the responsibility of the OCI holder to discolse his loss of citizenship and surrender the voters ID card ?

It is not clear whar needs to be done when one loses Indian citizenship...
Applying and getting OCI is in itself a humungous process (as made by the Indian high commision) but on top of this is there any booklet or information leaflet given on the tasks to be done once a person receives OCI card ?