eCl@ss is a system for classification and product description. For eCl@ss as a system to describe products, the most fundamental structural element is the property. A property describes a characteristic of a product. A property can have values which determine the most useful characteristics of the property (e.g. property: color, value: red). The sum of all values of a property is called a value list. Every value has a unique identifier (IRDI), a preferred name and a datatype - among other attributes that are described below.
 Element structure (Value)
The following part will describe how the structural element "value" is structured and which attributes it consists of. All attributes are named in CamelCase writing. Attributes can be mandatory or optional, can be created automatically or manually by the user and underly certain rules. All of them are limited to a certain amount of characters.
A value is in a relation to other structural elements.
 Identifier (Value)
The official and internationally unique eCl@ss identifier, i.e. primary key, is the IRDI (International Registration Data Identifier), a globally unambiguous identifier that comprises Supplier+TypeOfSE+Identifier+VersionNumber. The separate export of Supplier, ID, VersionNumber and the Identifier (ID+ VersionNumber) is therefore redundant. Starting with eCl@ss Release 8.0 this redundant information will no longer be additionally exported, because it is already contained in the IRDI which is the only valid primary key in eCl@ss.
The identifier for values is the IrdiVA. It is mandatory, automatically created and limited to 20 characters. TheTypeOfSE of a value is 07.
 Preferred Name (Value)
The text attribute named PreferredName is the official name of the value and is a mandatory text field. The following rules apply to the PreferredName:
- 80 character limit
- no special characters allowed
- Must not contain a trademark, company or brand name
- Give preference where possible to the basic grammatical form (singular, infinitive)
- The following special characters must be avoided: semicolons (;), inverted commas (")
 Definition (Value)
The value's definition is an optional text field. The rules to create a value definition are described below.
- 1023 character limit
- no special characters allowed
- shall be able to replace the preferred name in a continuous text without having to change it, i.e. the preferred name should not be repeated in the definition
- formal rules must be considered:
- start without a definite or indefinite article
- start with a lower case letter (unless it is a German noun)
- do not end with a full stop or any mark
Definitions should be complete and explain the meaning of the value. A definition must not be in the form of a request or contain a request. Phrasing such as "must", "is for", "it is needed" etc. must not be used. Definitions must not contain any units of measure (e.g. mm, °C etc.). For generally phrased denotations, create generally valid definitions, for more specific denotations, create correspondingly limited definitions.
 Data type (Value)
The value's data type defines what kind of information a value transports. It has to correspond to the data type of the property it is used for. The following data types are possible:
|BOOLEAN||Allowed values: (YES | NO)||Yes, No|
|STRING||A finite sequence of symbols that are chosen from a set or alphabet […] a sequence of characters (http://en.wikipedia.org/wiki/String_(computer_science)). Cannot be translated into other languages.||0173-1#01-ADG629#001 ; DN 700 ; 10 Mbps|
|STRING_TRANSLATABLE||A finite sequence of symbols that are chosen from a set or alphabet […] a sequence of characters (http://en.wikipedia.org/wiki/String_(computer_science)). Can be translated into other languages.||Red ; Green ; Aluminum|
|INTEGER_COUNT||data type which represents some finite subset of the mathematical integers. These are also known as integral data types. Used only for counting. (http://en.wikipedia.org/wiki/Integer_(computer_science)).||1 ; 10 ; 111|
|INTEGER_MEASURE||data type which represents some finite subset of the mathematical integers. These are also known as integral data types. Used for measuring in a specific unit of measure. (http://en.wikipedia.org/wiki/Integer_(computer_science)).||1 ; 10 ; 111|
|INTEGER_CURRENCY||data type which represents some finite subset of the mathematical integers. These are also known as integral data types. Used for measuring in a specific currency. (http://en.wikipedia.org/wiki/Integer_(computer_science)).||1 ; 10 ; 111|
|REAL_COUNT||a rational number expressed in decimal representation (http://en.wikipedia.org/wiki/Real_number). Used only for counting.||1,5 ; 102,35|
|REAL_MEASURE||a rational number expressed in decimal representation (http://en.wikipedia.org/wiki/Real_number). Used for measuring in a specific unit of measure.||1,5 ; 102,35|
|REAL_CURRENCY||a rational number expressed in decimal representation (http://en.wikipedia.org/wiki/Real_number). Used for measuring in a specific currency.||1,5 ; 102,35|
|RATIONAL||to represent rational numbers like 1/3 and -11/17 without rounding (http://en.wikipedia.org/wiki/Rational_data_type)%7Cstyle="border-style: solid; border-width: 0 1px 1px 0"| 1/3, 1 2/3|
|RATIONAL_MEASURE||to represent rational numbers like 1/3 and -11/17 without rounding (http://en.wikipedia.org/wiki/Rational_data_type). Used for measuring in a specific unit of measure.||1/3, 1 2/3|
|TIME||Format hh:mm according ISO 8601:2004||12:45|
|TIMESTAMP||Format yyyy-mm-dd hh:mm according ISO 8601:2004||1979-01-15T12:45:00Z|
|DATE||Format yyyy-mm-dd according ISO 8601:2004||1979-01-15|
|URL||According to ISO 13584-24:2003||http://www.eclass-contentdevelopmentplatform.com|
 Reference (Value)
In the field 'reference', only documents are to be mentioned, in which a definition of the preferred name exists explicitly as a definition. However, if only the theme of the preferred name is discussed, i.e. the norm does not contain a definition, the title of the norm can be mentioned. In the field 'reference', preference should be given to international, European or national norms. How to enter a reference: See ’The guideline for the creation of classes and properties in the DIN property dictionary’ (according to DIN 4002-4, DIN 820-2), e.g.:
- DIN EN ISO 11145:2006 07
- DIN 820-2:2004 10, 3.1
- ISO 1234:2006
If no norm is available, a URL is better than no reference at all. Unfortunately, the risk that a URL will become outdated is rather high.
 ISO Language Code
 ISO Country Code
 Release notes (Value)
The description of a value in the BASIC release notes is as follows (update: release 7.1):
 Usage of values
Values in eCl@ss are used as valid specifications of a property. eCl@ss has always interpreted the majority of values as being proposals. I.e. the value lists published before release 7.0 were seen as open, not exhaustive lists. With a few exceptions, eCl@ss cannot guarantee the exhaustiveness of its value lists because more values might be valid than already defined in eCl@ss. With release 7.0 eCl@ss has implemented changes in the data model so that a distinction is now made between restricted value lists and suggested value lists.
 Change Request
How to request a change on a value or a value list in the eCl@ss ContentDevelopmentPortal?
Please see here:
Rules for the creation of a change request are described here: General rules for Change Requests