Alphanumeric means something made of both letters and numbers. This can include any letter from the 26 in the alphabet and any number from 0 to 9. So m, k, z, r, e, f, 3, 25, 6, and 17 are all alphanumeric characters. The word alphanumeric is derived from the words alphabet and numerical. Conventional symbols, mathematical symbols, and punctuation marks are also used as alphanumeric characters. Examples of these are @, #, !, and *.
The characters can be written in upper or lowercase depending on whether the context it’s being used for is case sensitive. Alphanumeric characters can also be used in any order. Examples are bz3@llt, RdYw4!, and 982hfgq&667m.
Are There Exceptions to How Alphanumeric Characters Are Used?
When using alphanumeric characters to form passwords, the combination of characters used depends on the requirement of the program/company requesting a password. You may be restricted to a certain number of characters or only allowed to use uppercase, for example. You may have to combine precise types of characters, such as letters, numbers, and special characters as opposed to just letters and numbers.
A few numbers are also confused with letters easily so, sometimes, these characters are excluded. For example, auto manufacturers don’t use the letters O or Q because they can be misread for the number 0. Airlines don’t use the uppercase letter I in case it cannot be distinguished from the number 1. Other characters that are sometimes avoided because they are too similar are the number 2 and the letter Z, and the number 5 and the letter S. For handwritten alphanumerics, V is usually avoided as it can look similar to U.
Where Do You Commonly See Alphanumeric Characters?
Passwords are commonly made up of alphanumeric characters. The length, types of characters used, and whether the letters are upper or lowercase depends on the requirements of the company or program you are registering a password with. The longer the string of alphanumeric characters and the more types of characters used, the stronger the password is deemed to be. A computer keyboard has letters, numbers, and symbols on it, and is therefore classed as an alphanumeric keyboard.
What Other Uses Are There for Alphanumeric Characters?
A vehicle identification number (VIN) has a string of 17 alphanumeric characters. These are positioned very specifically to identify the country of manufacture, the manufacturer, the type of vehicle, the vehicle features, the check digit, the model year, the assembly plant, and the vehicle identifier section.
CAPTCHA images use alphanumeric characters for user authentication. These are generally short strings of characters that are distorted and contain a mix of upper and lowercase letters with numbers. Documents and databases contain alphanumeric characters, such as indexes and variable blocks.
Many companies use alphanumeric characters for brand names. This can be to specify certain models, such as iPhone 3G, iPhone 5s, and iPhone XR. The characters can refer to specific designs, such as Levi’s 510, or products, such as a V8 engine.
You’ll recognize brand names like the 3M Company, M&M’s, and 7-Up. Car manufacturers, in particular, love using alphanumeric characters to specify different car types. Examples of these include Jaguar XJ6, Hyundai i20, BMW 535i, Audi A4, and Mercedes E350.
ASCII stands for American Standard Code for Information Interchange. ASCII was the first set of characters used between computers accessing the Internet and was originally compiled in the 1960s.
Each code is a 7-bit set with 128 alphanumeric characters. As well as uppercase and lowercase letters, numbers, and punctuation, 32 control codes are also incorporated in these combinations. ASCII is what all character sets used for the Internet, in HTML, and within modern computers have been based on.