Hey gents, this will be a newbie question for most of you, but the answer has eluded me for a long time. Years ago I saw some trench coats and even some sports coats with this detail, and I tried to make a mental notation for the future when I would request this for a custom garment. Alas, it has been forgotten long since. And yes, I did search this forum thoroughly but to no avail. But luckily I recently found a picture which shows this exact accessory: It's the kidney bean shaped detachable 'latch' under the gentleman's collar. I'd like to ask, this is a trench coat feature first, and a sports coat feature second, correct? Any other garments you might find it on? It seems like a more casual, sporting look. Also, I seem to remember it being placed under the lapel, or even inside the coat itself. Does the placement vary? I thought I remember a picture of Prince Charles closing his lapels with it, not the collar. Thanks for any info you can give!