There are many different approaches to learning (and forgetting) cards. If you have an exam coming up with only new vocabulary, you will want to learn the newest cards first. On the other hand, if you want to test your long-term memory, you will want to review the oldest cards first. The most varied order is obviously a random order.
If you forget cards, you can put them on top of the unlearned batch to try to learn them again quickly. This can be annoying, however, if you consistenly can't remember that the capital of Sri Lanka is Sri Jayawardhenepura. Pauker can be configured so that the forgotten cards are put at the bottom of the unlearned pile. However, with some smaller lessons, it becomes likely that you are actually just memorizing the order of the cards as they appear. To solve this problem, you can configure Pauker to put incorrect cards anywhere in the unlearned batch.
When repeating cards by typing some people want to be very exactly and want Pauker to check for matching case. Other people do not care and feel more or less harassed by all those warning messages. This is why you can configure here if Pauker should match the case when repating by typing.