Values assigned to a nominal scale of measurement are

Numbers on a nominal scale are arbitrary labels that merely name or classify categories without quantity.

They are not permanent because any distinct code could replace another without loss of meaning.

They are not orderly since nominal categories carry no rank or sequence.

They are not meaningful as magnitudes because arithmetic on them is invalid.

The only legitimate operation on nominal values is counting frequencies in each category.

Gender and blood group are classic nominal variables.