The Document ID Service feature is useful to tag unique Id to documents across site collection to make it easier to retrieve. A prefix can be specified to use when the unique Id is generated. The document id settings is stored in the web property bag “docid_settings_ui” after the feature the activated. The web property bag can be updated using JSOM to assign a prefix with XML snippet like below. var docIdValue = ‘ ’ + docIDPrefix + ‘ true’ webProperties.