Red link is a non-verbal question
When you write a sentence in Scrapbox and then bracketing an important keyword, if it turns red, it means, "An explanation for this has not yet been written. ---
This page is auto-translated from /nishio/赤リンクは非言語的な問いかけ using DeepL. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.