...
Represents a set of properties with some kind of relationship. A 'blockdata' field can copy itself, to duplicate and create several sets. It can contain the following fields: <value>, <container>, <condition>, <function>, <dependencies>, and other <blockdata>
n - Name used to reference the field, especially when writing the .dat file.
There is a special blockdata name n='material' that has an extra meaning to declare that represents a material for import/export materials
name - Label that will be visualized by the user. It can be translated.
...