The phrase "alphabetical character" is correct and usable in written English.
It can be used when referring to a character that is part of the alphabet, typically in the context of programming, linguistics, or data entry.
Example: "Please ensure that your password contains at least one alphabetical character to enhance security."
Alternatives: "letter character" or "alphabetic character".
Moreover, they cannot display a whole book-size page of text, so Minsky included a second screen on his computer which had room for six thousand alphabetical characters, so that children could edit their compositions on it.
The latter part contains the strange myth of how Odin acquired the magical power of the runes (alphabetical characters) by hanging himself from a tree and suffering hunger and thirst for nine nights.
Carlos S. Glidden, an inventor who frequented the machine shop, became interested in the device and suggested that it might be adapted to print alphabetical characters as well.
Statistically different groups are denoted by different alphabetical characters in corresponding bar graphs.
The proposed descriptor preserves the alphabetical characters (e.g A, a, B, b, etc), special characters (e.g. ']',']'), and punctuations (e.g '.' ',') from both words.
Subjects were asked to indicate character repeats during a continuous serial display of randomly assembled alphabetical characters (n = 26) by pressing a key on a button box.
The data collection instrument consisted of answer choices represented by recognizable and familiar objects in the communities rather than alphabetical characters.
One of the challenges in analyses of protein sequence data in such repositories is the standard notation of sequences as strings of alphabetical characters.
Each query line must contain a sequence tag to be searched at the beginning of the line, optionally followed by a non-alphabetical character and arbitrary data on the rest of the line, which will be copied verbatim in the output.
