noun
Computing term for data consisting of letters and digits; the compound explicitly mentions European numerals and English letters.
このフィールドには欧数字英数字データのみ入力できます。
Only alphanumeric data can be entered in this field.
英数字 is the common word for alphanumeric characters; 欧数字英数字データ is a longer, more explicit compound used in technical contexts.
Compound of 欧数字 (European numerals), 英数字 (English letters), and データ (data).