Physics. the flow of a gas through a small orifice at such density that the mean distance between the molecules is large compared with the diameter of the orifice. Men who indulge themselves in writing anonymous accusations seldom limit themselves to one effusion.
There are times when you may want to use the 9 digit zip code validation for US. The 9 digit zip code is usually in format like this #####-####. For a 9 digit US zip code validation use below regular Expression. ^([0-9]{5}-[0-9]{4})$.
Validation Code. DEFINITION of 'Validation Code'. A series of three or four numbers on the front or back of a credit card that provide an additional layer of security when a credit card is used to make a purchase online or over the phone.