If you are working in a Proposal in the search function, you can just click on the flag button.
If you flag content, you can easily filter for that in the Knowledge Base. If that response happens to have an Reviewer assigned to it, that person will be notified.
You can see in the Knowledge Base how you can filter down on various Flag for Review options.
And here's how your responses are displayed. Now, appropriate content owners can make edits and turn off the review flag.