What Is Alphanumeric Characters?

What Is Alphanumeric Characters?

Alphanumeric Characters: Alphanumeric, also known as alphameric, simply refers to the type of Latin and Arabic characters representing the numbers 0 – 9, the letters A – Z (both uppercase and lowercase), and some common symbols such as @ # * and &.

Sites requesting that you create an alphanumeric password are asking us to use a combination of numbers and letters, which creates stronger passwords. We also use alphanumeric keys to create file names, although there are some symbols that are not accepted as part of a file name, such as a slash (/).

What Is Alphanumeric Characters?

That doesn’t seem very secret does it? The ‘secret’ language part comes into play when we start talking about alphanumeric characters in terms of actual computer programming.

What Are Alphanumeric Characters

Since computers (or central processing units, to be specific) use machine language in the form of numbers to communicate, computer programmers need to write their instructions using numbers rather than alphabet characters. To do this, programmers use numeric representations of what humans see as alphabet characters. You’ve probably seen or heard of binary code which uses only 0s and 1s to represent an alphanumeric character. Computer programmers can use a series of 0s and 1s to represent any character they wish. For example, in binary, the letter ‘A’ would be written as 01000001.

Another way computer programmers represent alphanumeric characters is to use ASCII. ASCII stands for American Standard Code for Information Interchange.

Partial ASCII Table

Using the ASCII table, a computer programmer can represent the word ‘red’ using the numbers 82 69 68. This is true unless they wanted it in lower case letters, in that case, it would be 114 101 100.

Now, you are probably thinking to yourself, ‘I can key those numbers from my keyboard or number pad, and all I get are numbers!’ You would be correct. In order to use those numbers as ASCII code, you need to be using a text-only program such as Notepad (or save a Word document as text only by choosing the plain text option).

Not only do you need to use a text-only file, but you also have to let your application know you want it to convert the code into alphanumeric characters by preceding the ASCII numbers with the ‘Alt’ key and using a numeric keypad such as the one found to the right of most keyboards. (If you are using a Mac, you will use the ‘Option’ key.)

How does this work? If you wanted to represent the letter ‘R’ (upper case), you would hold the ‘Alt’ key and then type the number 82 from the keypad. For ‘r ‘(lower case), you would hold the ‘Alt’ key and then type the number 114 on the keypad. This can be done with every alphanumeric character you want to create. Go ahead and try it! Open a blank file in notepad and press the series of keys described to try to produce ‘R’ and ‘r.’

Non-alphanumeric Characters

Alphanumeric, also referred to as alphameric, is a term that encompasses all of the letters and numerals in a given language set. In layouts designed for English language users, alphanumeric characters are those comprised of the combined set of the 26 alphabetic characters, A to Z, and the 10 Arabic numerals, 0 to 9.

For some computer purposes, such as file naming, alphanumeric characters are strictly limited to the 26 alphabetic characters and 10 numerals. However, for other applications, such as programming, other keyboard symbols are sometimes permitted. In some usages, the alphanumeric character set may include both upper and lower case letters, punctuation marks and symbols (such as @, &, and *, for example). For languages other than English, alphanumeric characters include letter variations such as é and ç.

The mishmash of letters and numerals used for texting abbreviations is sometimes referred to as alphanumeric. As is the case with the term alphanumeric, alphanumeric can be expanded to include other characters. The grawlix, for example, which represents a non-specific profanity, is generally made up of typographical symbols that do not include either letters or numerals, but it might be considered an alphanumeric word nevertheless.

When a string of mixed alphabets and numerals is presented for human interpretation, ambiguities arise. The most obvious is the similarity of the letters IO and Q to the numbers 1 and 0. Therefore, depending on the application, various subsets of the alphanumeric were adopted to avoid misinterpretation by humans.

In passenger aircraft, aircraft seat maps and seats were designated by row number followed by column letter. For wide-bodied jets, the seats can be 10 across, labeled ABC-DEFG-HJK. The letter I am skipped to avoid mistaking it as row number 1.

In-Vehicle Identification Number used by motor vehicle manufacturers, the letters IO and Q are omitted for their similarity to 1 or 0.

Tiny embossed letters are used to label pins on a V.35/M34 electrical connector. The letters IOQS, and Z were dropped to ease eye strain with 1053, and 2. That subset is named the DEC Alphabet after the company that first used it.

For alphanumerics that are frequently handwritten, in addition to I and OV is avoided because it looks like U in cursive, and Z for its similarity to 2.

Non-Alphanumeric Characters

Let’s examine that term: alphanumeric. That has two parts: “alpha” (a letter), and “numeric” (a number); the number should technically be “digit” but “alphadigitate” doesn’t sound quite right.

So, an alphanumeric password would have some combination of zero or more letters and zero or more digits. One that has 6–12 characters would have … well, that many characters.

So, a few examples would be





As a bonus, let’s see how many possible passwords there are of this form.

There are 10 possible digits, and 52 possible letters (when the case is considered).

The best way is to use a password manager like LastPass. it will generate completely random passwords for you of any length you want.

However, if you choose to create one yourself, try this method.

Pick a sentence that is easy for you to remember. Maybe a Bible verse, the pledge of allegiance, a line from your favorite book, etc. In this example, I will use the Pledge of Allegiance.

So the line is – I pledge allegiance to the flag of the United States of America.

Take the first letter of each word – ipattfotusoa

Now add a number at the front or back, or both – 34ipattfotusoa87

Now change one or two of the letters to upper case – 34IpattfotUsoa87

Finally, add one special character to it – 34IpattfotU$oa87

You just created a very unique password that is something you can remember. This password is 15 characters long, uses both upper and lower letters, numbers, and special characters. It would be very resistant to cracking.

You can also vary this approach, leaving out characters as long as you keep the password long. The numbers can also be those that are important to you such as birth dates. Normally the advice is to avoid those kinds of numbers but in this instance, since the base password is pretty random, it won’t hurt. It’s very unlikely an attacker could create a dictionary to crack this.

Please don’t use this actual password. Find your own sentence and then make it unique to you.

What Is Alphanumeric Characters

Be creative and have some fun.. like ADC12$&5as!!! Or try a password generator online or within a password saver program (you are using one, right?). Remember each request for you to create a password will come with its own set of requirements (length, upper/lower case, nonnumeric characters) so please read that carefully. If you don’t meet the requirements, the password will be rejected.

Any combination of letters and numbers would be alphanumeric. Real words, common numbers, and patterns make weak passwords. Names of people close to you, their dates of birth or yours are also weak.

This is why WiFi passwords are generally complete nonsense and written down forever. Ridiculously hard to remember, no way of linking them to their owners.

TkTkLtSHI1dWYA could be an example. It’s actually lyrics to a nursery rhyme. So easily remembered but still very strong. Unless everyone starts using it.

Your password can be on any phrase subject example The Rain in Spain 3 19 35 ///$ alphanumeric means letters to form a word followed by a numeral for a string of numbers followed by symbol the password does not have to make any sense it has to be complicated so it cannot be hacked

Important note writes the password down not on any computer or iPad iPhone etc good old fashioned notebook, will, do and keep it in a safe place do not give it to anyone.

Alphanumeric Characters List

The VIN is a 17-digit alphanumeric character vector code. The characters used do not include the letters I, O, Q, or Z to avoid confusion with digits. The vector components are fixed length and use this format:

Position 1 identifies the country of manufacture.

For example: U.S. (1 or 4), Canada(2), Mexico(3), Japan(J), Korea(K), England(S), Germany(W), Italy(Z)

Position 2 identifies the manufacturer. For example; Audi(A),

BMW(B), Buick(4), Cadillac(6), Chevrolet(1), Chrysler(C), Dodge(B),

Ford(F), GM Canada(7), General Motors(G), Honda(H), Jaguar(A), Lincoln(L), Mercedes Benz(D), Mercury(M), Nissan(N), Oldsmobile(3), Pontiac(2 or 5), Plymouth(P), Saturn(8), Toyota(T), Volvo(V).

Position 3 identifies vehicle type or manufacturing division.

This substring of 3 characters is called the World Manufacturer Identifier or WMI code.

Positions 4 to 8 are used by the manufacturer to identify vehicle features such as body style, engine type, model, series, etc.

Position 9 is the check digit.

A check digit has been part of each VIN since 1981. The VINs of any two vehicles manufactured within a 30-year period cannot be identical. After all other characters in the VIN have been determined by the manufacturer, the check digit is calculated with a MOD(11) weighted sum algorithm, so the check digit will be zero through nine (0–9) or the letter “X” if the remainder is 10.

As usual, the letters have to be mapped to a numerical value (remember I, O, and Q are not allowed) and digits use their own values:

A: 1 G: 7 N: 5 V: 5
B: 2 H: 8 P: 7 W: 6
C: 3 J: 1 R: 9 X: 7
D: 4 K: 2 S: 2 Y: 8
E: 5 L: 3 T: 3 Z: 9
F: 6 M: 4 U: 4


The weights for each position in the VIN except the 9th position, which is where the results of this computation will go, are:

1st: X8 5th: X4 10th: X9 14th: X5
2nd: X7 6th: X3 11th: X8 15th: X4
3rd: X6 7th: X2 12th: X7 16th: X3
4th: X5 8th: X10 13th: X6 17th: X2

Multiply the weights and the numerical values, sum the resulting products, and perform the MOD(11) computation. If the remainder is 10, the check digit is the letter X. Valid check digits also run through the numbers 0 to 9.