Topic에서 고정(Pin) 기능을 발견했는데, 이건 중첩 모드에서만 사용할 수 있나요?

I noticed that nested Topics can have a Pin feature, but it disappears when I read in Flat mode. Is this feature only available in nested mode, or is there more to it? I’m really looking forward to this feature.

I’m replying to see if I can set this as a Pin.

Yes, this is only available on nested mode.