Hold one shape in mind: a strip of cloth that starts wide at the pole and to a point, snapping in the wind. It is made to be seen from far away and read at a glance. On a ship that glance is a message; on a fence or a bedroom wall it is a name, a class, a team.
Wiktionary traces pennant through Middle English penon and Old French penon to Latin penna, a feather, and links it to pennon and pinion. A feather is long, thin and pointed, which is the shape of the flag.
根據 Wiktionary，pennant 經由中古英文 penon、古法文 penon，回到拉丁文 penna（羽毛），同一家族還有 pennon 和 pinion。羽毛細長、末端收尖，正好就是這種旗子的形狀，字義和形狀對得很準。
Wiktionary entry for pennant (packet evidence kaikki:3f6f69a190036ae4:467429863): From Middle English penon, Old French penon, from Latin penna (feather).
Two branches
細長帶尖角的旗
這一支就是核心畫面本身：實體的旗，用來打信號或表明身分。
noun · B2
A long narrow flag with a pointed end. Ships fly pennants as signals or to show who is on board, and schools, clubs and sports teams use them, often as small triangular flags in the team's colours.
三角旗、長條尖角旗
用旗代表的冠軍頭銜
球隊贏了會升起那面旗，旗子看得見、掛得住，久了就用旗名代替頭銜本身。
noun · B2
In American baseball, the title won by the best team in the American League or in the National League. A team that finishes first wins the pennant.
聯盟冠軍（美國棒球）