After boggling some minds with its naming system for COVID variants, the World Health Organization made some clarifications on Saturday. In a statement, the agency explained why it skipped over the Greek letters “Nu” and “Xi” when naming the new, highly transmissible Omicron variant. It said “Nu” was skipped because of its semblance to “new,” while “Xi” was passed over because of its use as a common surname around the world. It said it had rules preventing the use of variant names that could cause “offense to any cultural, social, national, regional, professional, or ethnic groups”—though it did not specifically address speculation about the WHO’s supposed deference to Chinese leader Xi Jinping. The organization labeled the Omicron variant a “variant of concern” on Friday.