Originally Posted by
paulmoscow
I've written here twice: my banks inform me through SMS about every single transaction, either approved or declined. These SMS have exact sums and merchant names which in themselves sometimes quite funny.
It's a special kind of authorization and it may not appear in your SMSs; for example, Visa requires restaurants to put in for the check amount for an authorization, but returns an authorization based on the check amount plus 20%.
"Visa protects you! – An authorization obtained by a restaurant is valid for that
amount plus 20 percent"
http://usa.visa.com/download/merchants/rest_own_mgr.pdf