This script implements the Publisher Common ID (PubCID) framework, providing functionality for websites to create and manage a consistent, privacy-centric identifier for their users. PubCID is an open-source, cookie-based identifier designed as an alternative to third-party cookies, facilitating audience recognition and measurement across various advertising platforms. Upon execution, the script verifies the presence of an existing PubCID in the user's browser, generates a new one if none is found, and manages its lifecycle and renewal. This ID is stored in a first-party cookie, linking a user's browser to an anonymized identifier across a publisher's domain. The standardized PubCID can then be leveraged by integrated ad tech vendors for purposes like targeted advertising, frequency capping, and campaign attribution, while aiming to enhance transparency and user privacy.