A more thorough explanation:

IN PLENO LUMINE

in pleno lumine (in plee-noh loo-muh-nee) is an adverb and adjective that means "in the light of day," "in common knowledge," or "in public."

• The company's financial records were made public in pleno lumine during the trial.
• The politician's scandal was exposed in pleno lumine by the media.

These examples illustrate how something is made known to the public or in common knowledge. The phrase emphasizes that something is not hidden or secret, but rather out in the open for all to see.