Batch QA (Quality Assurance) is a tool that checks the entirety of a translated document for errors (see article here). Administrators can force a batch QA check to be run before any document is marked as completed by a translator or reviewer.
To enable this feature, go to the Organization tab (only visible to administrators), and then select Settings. You will have the option to separately toggle mandatory batch QA checking for translators and reviewers.
When the setting is enabled, upon attempting to mark a document for completion, the translator or reviewer will be prompted to first run a batch QA check on the document. The setting is disabled by default.