# Commission Implementing Regulation (EU) 2015/2447 of 24 November 2015 laying down detailed rules for implementing certain provisions of Regulation (EU) No 952/2013 of the European Parliament and of the Council laying down the Union Customs Code, Division 7: The term ‘type/length’ in the explanation of an attribute indicates the requirements for the data type and the data length. The codes for the data types are as follows:


a alphabetic
n numeric
an alphanumeric
The number following the code indicates the admissible data length. The following applies:
The optional two dots before the length indicator mean that the data has no fixed length, but it can have up to a number of digits, as specified by the length indicator. A comma in the data length means that the attribute can hold decimals, the digit before the comma indicates the total length of the attribute, the digit after the comma indicates the maximum number of digits after the decimal point.
Examples of field lengths and formats:
a1 1 alphabetic character, fixed length
n2 2 numeric characters, fixed length
an3 3 alphanumeric characters, fixed length
a..4 up to 4 alphabetic characters
n..5 up to 5 numeric characters
an..6 up to 6 alphanumeric characters
n..7,2 up to 7 numeric characters including maximum 2 decimals, a delimiter being allowed to float.

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Source: https://www.legislation.gov.uk/eur/2015/2447/attachment/2/division/FORMATS AND CODES OF THE COMMON DATA REQUIREMENTS FOR APPLICATIONS AND DECISIONS/division/7. (the official version)
Page: https://openlegislation.uk/eu-regulation-2015-2447/attachment-2/division-FORMATS AND CODES OF THE COMMON DATA REQUIREMENTS FOR APPLICATIONS AND DECISIONS/division-7.
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.