set of distinct values, characterized by properties of those values, and by operations on those values
[ISO/IEC 11404:2007, definition 4.11]
unit of data for which the definition, identification, representation, and permissible values are specified by means of a set of attributes.
[ISO/IEC 11179-1:2004, definition 3.3.8]
specification of the pattern that members of of set of data must adhere to, including data type, constraints, combination, and logical expressions
EXAMPLE 1 The statement that the material for a bracket is either ALUMINUM ALLOY, MIL-R-12545, ALLOY 6061 or ALUMINUM ALLOY, QQ-A-601, CLASS 9, COND F (and nothing else) is an example of a logical expression.
EXAMPLE 2 The statement that a pump's housing material can be a combination of ALUMINUM ALLOY 6061 and CHROMIUM, QQ-C-320, TYPE 1, CLASS 2D is an example of the specification of a combination.
preconceived form pattern that has some specific engineering meaning
NOTE Properties can be assigned to features, independently of other features or of an item as a whole.
EXAMPLE Examples of features for a bearing include:
case
core
external cylindrical surface
flange
flat bearing surface
intermediate layer
internal race insert
race insert(s)
race liner (nonmetallic material)
spherical surface of race insert
vertical counterbore surface