《左傳．僖公二十八年》於城濮之戰後又云：「城濮之戰，晉中軍風於澤，亡大旆之左旃。」「亡大旆之左旃」此事對城濮之戰有何影響？此事若至關重要，何以僅附之於後？此事若無關緊要，又何必提及？針對相關的問題，本文擬先論旗物與旗名，續論左旃，遂釋「亡大旆之左旃」云，蓋大斾己別論矣。

After narrating the war of Ch’eng-p’u, on the 28th year of Duke of Hsi, Tso-chuan says: ”On the War of Ch’eng-p’u, the main brigade lost their cows, horses, and left flag around the swamp.” What was the consequences of this event? If it is significant, why does the author only attaches it at the end of his narration? If it is not important, why does the author even bother to mention it? This article deals with the issue of the name of the flag and the left flag. As for the magnificent flag, I have already discussed it on other article.