While preparing to migrate from Innovative Interfaces' text-based serials module to its new Millennium Serials product, the author, a manager of technical services operations in a small academic library, found herself faced with a number of decisions regarding how to store holdings information. Holdings data is information about individual items that a library owns or has purchased access to. For monographs, holdings information generally includes things like the call number and bar code assigned to an individual physical item. For serials, it is publication pattern, subscription status, and the numbering and dates associated with individual issues. A uniform resource locator (URL) or other identifier that supports linking directly to a particular work is a vital piece of holdings data for a remote access electronic resource. In this article, the author shares what she has learned in the hope that it will assist those in a situation similar to hers. She also hopes to promote a broader understanding of current holdings standards and associated issues.