Definition from Wiktionary, the free dictionary
- (idiomatic) A cue, warning, or alert; a sign or signal that something is wrong.
- Improper formatting is a red flag to look for other problems with the data.
- 2012, Alan Rappeport, Financial Times, Eli Lilly settles bribery charges
- The US Securities and Exchange Commission alleged that Eli Lilly subsidiaries funnelled millions of dollars to government employees in other countries to secure business and did little to follow up on red flags.
- (politics) A common symbol, usually in the form of a banner, for leftist revolutionary ideologies, especially socialism.