A document is marked as generated by Mergeservice when the APXT_Redlining__Is_Mergeservice_File__c checkbox is set to true on the Content Version record.
The checkbox sets to true automatically when using the Generate Document Mergeservice button on the Contract Agreement object. When you click the Open & Edit button beside the file, it opens to review and edit using Online Contract Collaboration.
To open and edit your documents in Online Contract Collaboration, take the following steps:
From the Conga CLM (Contracts for Salesforce) application, navigate to the Contract Agreements tab.