### Layout file structure

The layout file refers to the content of the microdata file, it describes the information on each survey variable.
Firstly, the survey name, the reference period of data and the layout length (number of bytes) are given, then for each variable the following information are provided:

Field Name | Description
Ordinal N° | Variable sequence
Length | Variable length
Field name | Short name of the variable in the layout (es: unique number identifying the questionnaire's question)
Variable type | In case of a categorical variable, the code list associated is displayed selecting categorical
Aggregation | The name of the variable that aggregates the described variable (e.g. 'Province' variable aggregates 'Municipality' variable)
Notes | Any further information regarding variable
Record type | If there are different record type value in the layout structure, it means that there are more than one varable describing the same position in the record layout.
Variable name | Extended description of the variable (e.g. questionnaire's question)
Field format | A as 'alphabetical' or N as 'numeric'
Decimal number | In case of numerical variable, the number of decimal digits is shown
Decimal separator | The character adopted as separator between integer and decimal digits
Arithmetical sign | If present, arithmetical sign is shown as '+' or '-'
Measurement unit | Measurement unit of each variable

An example of layout

SURVEY: Survey name Year 2005
Layout length: 227 bytes

Ordinal Num | Length | FieldName | Variable type | Aggregation | Notes | Record type | Variable name | Field Format | Decimal Number | Decimal separator | Arithmetical sign | Measurement unit
1 | 6 | Id |  |  |  | 0 | Sequence | A |  |  |  |
... | ... |  |  |  |  |  |  |  |  |  |  |
3 | 3 | nuts | categorical |  |  | 0 | Geografical location | A |  |  |  |
... | ... |  |  |  |  |  |  |  |  |  |  |
15 | 11 | turnmar |  |  | . : missing | 0 | Turnover share 2004 | N | 9 | , |  |
... | ... |  |  |  |  |  |  |  |  |  |  |

In this example, 'turnmar' variable is numeric, it is composed by 11 digits (Length), 9 (Decimal Number) specifies the number of decimal digit and the decimal separator is ',' . Moreover, 'Notes' field indicates that '.' means 'missing'.