How to cancel a custom study which did not created a deck?

[addons_zz]

Searching, I found this thread: How to remove Custom Study Session? - #4 by ODeer

But it did not mention how it would cancel a custom study which increased today’s limit.

Look at the documentation for this:

Increase today’s new card limit

Add more new cards to the deck you are currently studying. Note that unlike other options, this does ‘not’ create a new filtered deck, it modifies the existing deck.
Filtered Decks - Anki Manual

When it creates a new deck, I suppose I can delete it. But when it increases today’s limit, how to decrease it back?

[jcznk]

You can decrease it back by using Custom Study again and inputting a negative value

E.g.