The antonyms for "brought in to the open" could be "kept hidden," "concealed," or "covered up." These terms imply that the information or issue in question is purposely obscured or not divulged. Other antonyms could include "ignored," "suppressed," or "buried," indicating that the topic is either unrecognized or deliberately avoided. The opposite could also be "handled privately," "resolved directly," or "addressed discreetly," suggesting that the problem was dealt with behind closed doors or without public attention. Ultimately, the antonyms for "brought in to the open" vary depending on the context and the reason for not disclosing the information.