The term nominalism refers to the belief that general ideas are names without any corresponding reality. It also believes that only particular objects actually exist.
Nominal size is the size of the largest aggregate in a grading.
nominal bore
nominal wages
Mean
Nominal numbers are numbers used for identification only. They do not indicate quantity, rank, or any other measurement. The properties of nominal numbers are the minimum required to refer to an entity as a number. The term "nominal number" is quite recent, and appears to have originated as a usage in school textbooks derived from the statistical term "nominal data", defined as data indicating "...merely statements of qualitative category of membership." Mathematicians would typically describe this concept simply as a mapping between objects, or sets of objects, to the ordinal numbers.
nominal wages
A nominal interest rate is an interest rate that does not factor in the rate on inflation. Nominal interest rate could also refer to an interest rate that does not adjust for the full effect of compounding.
That means Nominal Diameter is 300 mm
NB (nominal bore) is the European designation equivalent to NPS is DN (diamètre nominal/nominal diameter/Durchmesser nach Norm), in which sizes are measured in millimeters. NB (nominal bore) is also frequently used interchangeably with NPS.You can refer more details herehttp://www.piping-engineering.com/nominal-pipe-size-nps-nominal-bore-nb-outside-diameter-od.html
DN": Diametre nominel - Nominal diameter of the valve, and "50" is the size of the valve in [mm]. Alternative is NPS (Nominal pipe size in inches).
It means the parking with lots of facilities in a very nominal cost.
NB stands for Nominal Bore.