I hope my twelve year old self can be forgiven for not knowing that these jaunty little numbers are known as tabards, instead conflating tabards with scabbards. It took some time to realize that tabards are distinct from scabbards in a very obvious way: while both are worn items, scabbards are sheaths meant to hold bladed weapons, while tabards are outerwear intended to assist in identifying friend from foe on a battlefield.
Awareness of the difference between the two improved my understanding the significance of the Imperial Tabard treasure in Avalon Hill's Magic Realm.
There are three treasures in Magic Realm that, in combination, represent the Imperial Regalia. The first is the Imperial Tabard. While worth only 17 Gold if sold, the Guard award you with 20 Fame if you return it to them, as it represents the office of the long-departed King, whom the Guard loyally served. This treasure is perhaps the only one in the Magic Realm game with no spell or in-game effect attached.
The second Imperial treasure is the King's Golden Crown. A heavy treasure, worth 50 Gold, it too attracts 20 Fame if sold to the Guard. It can be used as medium armor against smash attacks, but I can't see many players risking a treasure this valuable in such reckless fashion.
The final Imperial treasure is the Royal Sceptre. While this is worth only 8 Gold, it can be sold to the Guard for an additional 20 Fame. The Royal Sceptre's in-game effect is to permit an extra HIRE phase each game-day. That is a powerful advantage to the many Magic Realm characters whose winning strategies rely on hiring and controlling henchmen in order to fulfil their victory conditions. It is often better for those characters to hold on to the Royal Sceptre, despite the tempting Fame reward that comes with its sale to the Guard.