The new attribute block is located in the Categories drawer of the Blawx toolbox.
The new attribute block is used to add an attribute to a category.
The new attribute block must be placed inside a category attribute block, and applies to the category named in the category attribute block. It requires an attribute name, which must begin with a lowercase letter and not include spaces. It also requires a data type, which must be one of the datatype blocks in the Data Types drawer of the Blawx toolbox, or a category.
Note that if you specify a data type, and not a category, your attribute selector blocks for that attribute will only accept the right type of value, and variables. If you choose a category as the data type, your attribute selector blocks will accept any object, or variables.
Attribute names should be unique, even as between different categories.