Some of us see churning as a sport; others like myself consider it more of an art. For this reason I would like to perfect my art. What does it mean when we say that you can apply for a Bank of America or Chase card every 30 days?

30 days after you apply?
30 days after something happens in the inner workings of the bank?
30 days after you receive and activate the card?
30 days since your last application for any card or 30 days since you applied with a different department e.g. Bank of America business vs. personal?

I welcome the input here.

Cheers ^