What does the red proofreading symbol indicate to the writer?

a mark to indicate where a correction is needed.

it is to indiacate when the correction is needed

based on the biblical principle proverbs 16: 32, i agree with the author of the passage "better is it that it takes longer to be angry than the strong " to the extent that i share the philosophy that the nobility of heart demonstrates the strength of a person. those who are very proud, get angry easily and show their anger toward others are really weak, but those who are noble and do not constantly obfuscate or contain their feelings of anger, are strong people