在本文中，我們介紹了三個跟metadata相關的標準，它們分別是FGDC的Digital Geospatial Metadata、Dublin Core、和URC。雖然它們各有自己的設計目標和特質，但 都是假設其操作環境為類似網際網路的環境。FGDC的Digital Geospatial Metadata是設 計來專門處理地理性資料，由於它有聯邦行政命令的支持，可說是已成為美國在地理方 面的資料著錄國家標準。Dublin Core則比較像是USMARC的網路縮版，使非專業人士也能 在短時間內熟悉和使用此格式來著錄收藏資料，但在現階段祇針對類似傳統印刷品的電子 文件。由IETF的URI工作小組所負責的URC，其原始的設計目的雖是用來連結URL和URN，但 為因應電子圖書館時代的要求，其內涵逐漸擴大，雖然尚在發展中，但由於有IETF的支持 ，未來成為網際網路上通用標準的可能性極大。在此文中，我們也從幾個不同角度，分析 和比較這三個metadata格式的異同和優缺點。

　　　　　In this work, we introduce three metadata related standards. The first standard is Digital Geospatial Metadata which was created by FDGC on June, 8, 1994 under the orders of US Executive Order 12906. The second one. the Dublin Core, is the product of OCLC/NSCA Metadata workshop held in 1995. The last one is URC which is still under construction and supervised by the URI Working Group of IETF. Although these three different metadata standards have their own objectives and characteristics, they all emphasize Internet-like working environment. The first two aim at more specific types of data; The Digital Geospatial Metadata is designed for geospatial data while the Dublin Core is like an abbreviated network version of USMARC to handle document-like objects. On the other hand, URC is the most comprehensive metadata format among them and can be applied to all kinds of documents on Internet.