中文摘要：

SNOMED CT中的概念都通过层级关系相连.介绍了目前SNOMD CT的概念层级结构及分类情况,包括新增加的＂元数据层级＂、＂根元数据概念＂;还介绍了常用的几个标识符及SNOMED CT标识符（SCTID）的结构,包括数据类型、扩展、约束条件、验校码、分区标识符、命名空间等,为学习和借鉴SNOMD CT的标准化方法提供资料.

英文摘要：

Concepts within SNOMED CT are related to each other by hierarchical relationships. The current SNOMED CT hierarchy structure and classification are introduced, as well as the added information about metadata hierarchy and Root Metadata Concept. And several identifiers are introduced including SCTID structure, Data Type, Extensions, Constraints, Check-digit, Partition-identifier, Extension namespaces, and so on.