Zip Codes - 11 Digit

This dataset is the Maryland ZIP codes based on the most current MD PropertyView data. In 1993, the Maryland Department of Planning and the Maryland State Highway Administration entered into a Data Base Usage Agreement with Bell Atlantic and Data Chromatics, Inc. to develop an enhanced street address map for Maryland. Zip Code boundary area files were one of the products derived from this partnership. The resulting boundary area files were intended to improve the cartographic quality and accuracy of the zip code boundary area files derived from the U.S. Census Bureau's post 1990 Census TIGER\Line Files (based on the Census Bureau's zip code tabulation areas, ZCTAs). Subsequent iterative improvements to the Zip Code boundary area files have been made using premise address information associated with mapped parcel records as provided in the Maryland Department of Planning's MdProperty View GIS product. The resulting files are meant to serve as a "good approximation" of zip codes as polygons (which in reality they are not) but are not official Zip Code maps and are not meant to be a substitute for any products offered by the U.S. Postal Service, the official source for zip code information. While there are no restrictions on their use we do recommend that they are best used with MdProperty View and that MDP makes no guarantee or warranty regarding the files. For information on the date of the data to each jurisdiction's corresponding MdProperty View edition, see the production schedule located here: https://planning.maryland.gov/Documents/OurProducts/PropertyMapProducts/Sched.pdf.

本数据集为基于最新版马里兰州PropertyView数据编制的马里兰州邮政编码区域数据集。1993年，马里兰州规划局（Maryland Department of Planning）与马里兰州州公路管理局（Maryland State Highway Administration）签订数据库使用协议，合作方包括贝尔大西洋公司（Bell Atlantic）及Data Chromatics, Inc.，旨在开发马里兰州的增强型街道地址地图。邮政编码边界区域文件便是该合作项目产出的产品之一。

此次产出的边界区域文件，旨在提升源自美国人口普查局（U.S. Census Bureau）1990年后人口普查TIGER/Line文件（基于普查局邮政编码制表区域（ZCTAs））的邮政编码边界区域文件的制图质量与精度。后续团队依托马里兰州规划局MdProperty View地理信息系统（GIS）产品中提供的映射宗地记录关联的楼宇地址信息，对该邮政编码边界区域文件进行了多轮迭代优化。

最终产出的文件仅可作为邮政编码多边形的“良好近似”（现实中邮政编码并非多边形形态），且并非官方邮政编码地图，不可替代美国邮政服务局（U.S. Postal Service，邮政编码信息的官方来源）推出的任何相关产品。尽管该数据集的使用无任何限制，但我们建议其最好与MdProperty View配套使用，且马里兰州规划局不对该数据集作出任何保证或担保。如需了解各辖区对应MdProperty View版本的数据日期，请参阅此处的制作时间表：https://planning.maryland.gov/Documents/OurProducts/PropertyMapProducts/Sched.pdf。