This report describes the ISO TC211 codelist catalogs, the codelists they contain, and the values and definitions of the codes.
Please contact Ted Habermann if you have questions or suggestions.
| Entry | Definition | 
|---|---|
| class | descriptor of a set of objects that share the same attributes, operations, methods, relationships, and behaviour | 
| codelist | flexible enumeration useful for expressing a long list of values, can be extended | 
| enumeration | data type whose instances form a list of named literal values, not extendable | 
| codelistElement | permissible value for a codelist or enumeration | 
| abstractClass | class that cannot be directly instantiated | 
| aggregateClass | class that is composed of classes it is connected to by an aggregate relationship | 
| specifiedClass | subclass that may be substituted for its superclass | 
| datatypeClass | class with few or no operations whose primary purpose is to hold the abstract state of another class for transmittal, storage, encoding or persistent storage | 
| interfaceClass | named set of operations that characterize the behaviour of an element | 
| unionClass | class describing a selection of one of the specified types | 
| metaClass | class whose instances are classes | 
| typeClass | class used for specification of a domain of instances (objects), together with the operations applicable to the objects. A type may have attributes and associations | 
| characterString | textual information | 
| integer | numerical field | 
| association | semantic relationship between two classes that involves connections among their instances | 
| Entry | Definition | 
|---|---|
| mandatory | element is always required | 
| optional | element is not required | 
| conditional | element is required when a specific condition is met |