Something I would say infrequently and irregularly on the only other social service I've ever used, and will translate to the #Fediverse:

All boosts, re-toots or re-posts (or whatever they're called) from this account are to be considered endorsements. If I don't endorse the post, I will either not boost, re-toot or re-post it, *or* it will be clear in my comment accompanying the boost, re-toot or re-post.