Over the weekend, we quietly introduced a new feature to our comment threads.

It’s one we hope NOT to use often but one that we expect will have a big impact when we do. We recently finished work on what we’re calling “moderated comments.” In certain, select, circumstances, it allows us to pre-approve comments before they go live on our site.

On the story this weekend about two women who fell off a retaining wall, we enabled moderated comments. We didn’t, however, turn it on as soon as I would have liked. Part of using this new technology will be figuring out when we want to use it.

Off the bat, I can tell you we’re extremely likely to use it when we’re dealing with a story that is about someone who may be fighting for their life. We’re also likely to use it when we write a story that could lead to comments attacking children. I can also tell you we’re extremely unlikely to use it when we would be the target of criticism. In fact, as you can see from our guidelines , correcting misinformation in a story or providing context to our reporting is a category of information we want to encourage.

Ultimately, our goal is to continue to encourage the free exchange of ideas that our comment threads are known for, but also limit the types of damaging, hurtful comments that often come from accidents or crimes. We hope to use this feature once a week or less. If you have questions or comments on the new feature — or on when and how we should use it — please leave a comment below or contact me directly