noun
supplementary symbol
Technical term for symbols such as numbers, punctuation marks, and other non-letter characters used in writing systems.
補助記号には、数字や句読点などが含まれる。
Supplementary symbols include numbers, punctuation marks, and the like.
記号 is a broader term for any symbol or sign, while 補助記号 specifically refers to auxiliary symbols like punctuation and numerals.
Compound of 補助 (ほじょ, 'supplementary') and 記号 (きごう, 'symbol').