The phrase 'alpha characters' is correct and usable in written English.
You can use it when referring to the 26 letters in the English alphabet. For example, "This word scramble only requires alpha characters, so you don't need to worry about numbers or special punctuation marks."
So, how secure are you with that secret password of yours, that singular protective word that's supposed to consist of both upper case, lower case string of alpha characters and numerics that you can barely remember?
He instituted an elaborate internal communications system to reduce the sense of isolation that their captors tried to create, which used a five-by-five matrix of tap codes for alpha characters.
Masking replaces numeric characters between "1 and 9" with "9", lower case alpha characters "a to z" with "z" and upper case "A to Z" with "Z".
There's somebody for every kid to identify with, and there's no alpha character.
In that self-serious but addictively trashy nighttime soap opera by Shonda Rhimes, the Washington fixer played by Kerry Washington is the heroine and alpha character — even the president, an ex-lover, has to beg for her attention.
Fletcher and his team were asked to make it easier for witnesses of hit-and-run accidents to remember the number plate, so they added an alpha character to the end of the existing six-digit sequential system.
Blue chip companies like Microsoft, Google and Amazon all use questions like, "Write a function that takes a string consisting of numeral characters and returns all possible alpha character strings of same length as input that correspond to the keypad of a typical telephone," in order to separate the skilled coders from the chaff.
You can use other keys in combination, but at least one key must be an alpha character, along with at least two "other" keys held down along with the alpha character.
This means, e.g., you must have quotes around attributes that have non-alpha characters in them.
She brings off a mix of confidence, bewilderment and vulnerability, which functions very well against the alpha male characters higher up the chain of command.
The woman in question, Carla Gugino, was once a model, yes, but she now enchants to more complicated ends in film and television, as alpha female characters whose flaws are explored with absolutely no pity.
