### Symbol layer model:

The symbol layers may have the following optional fields:

- a real number field to store the symbol rotation (degree counterclockwise where zero = horizontal to the right)
- a real number field to store the symbol scale

The symbol layer can be defined with a style set as follows:

- If you decide to handle the rotation or scale of symbols then the <Style>-<Single Symbol> option and <Style>-<map units> option must be enabled
- The rotation could be read by a real number field that stores the symbol rotation through the formula "360-<field that stores the rotation>" (degree counterclockwise where zero = horizontal to the right, <Style>-<Advanced> option "rotation field name"-<Espressione>, if set than the INSERT command will ask for it)
- The scale can be read by a real number field that stores the scale of the symbol (<Style>-<Advanced>-<Size scale field>-“ field that stores the scale” and <Style>-< Advanced >-<Size scale field >-<Scale diameter>, if set than the INSERT command will ask for it)