The 'love token' meaning is bookish and shows up most in Ming-Qing fiction, period dramas, and translated Japanese (the Japanese
表記 hyōki, 'notation/written form', has been re-borrowed into modern Chinese linguistics writing — that's the second sense). In everyday Chinese you'd say
信物 (xìnwù) for a love token and
标记 (biāojì) for notation.
