Online Field Attributes
Fields have certain characteristics, or attributes, that determine data display and entry. For example, a field has a type and a size, some fields are key fields (that is, they belong to an index), the content of some fields can be restricted to certain values, and so on.
The database definition determines the initial attributes for a field. You can change some of these attributes when you paint a field on a form. Because different field types have different attributes, some attributes are not available for certain fields. For example, if a field has no values defined in the database, that field has no value, default, or translation attributes.