[shlewis]

This is an extreme level of pedantry(forgive me), but there is a subtle difference between "DC" and "할인" (and also "세일").

"할인" refers to a wide variety of discounts: it may have a few conditions (minimum quantity, membership, etc.), be available only for a certain period of time, or be a fixed amount or percentage.

"세일" is pretty much the same, although it puts a tiny bit more focus on being a limited-time offer and being percentage-based.

"DC" almost always refers only to a simple, percentage-based discount or rounding down the price. It also sounds much more spontaneous and less formal.

[GreenDolphinSys]

No need for forgiveness, I appreciate the pedantry and explanations. Personal grips aside, I'm forever a student of the language.