This could well be a "Canadian thing". I often joke in that manner, but am being serious here - it may be due to differences in banking/financing/retail laws between our countries.
But..... maybe not. What I stumbled upon was definitely a glimpse "behind the curtain, at the shadowy figure pulling the levers". Simply put, the amounts I describe never appeared on my printed statements (I don't bank online). Back then, I was doing a great deal of driving for business, and was regularily using my Ccard at the pump - point being, these ghost background transactions (that were secretly tying up my credit, short term) must have been filtered out when my monthly statements were printed. I only found out about this practice during a detailed phone discussion with my Ccard company, concerning a purchase un-related to gasoline stations.
There is an industry term (that I've forgotten) for what they are doing - something like "reserving credit", but that's not it, it is a more accurately descriptive wording. A couple of years later, I had another conversation with my Ccard company about this practice - that's where this terminology came up. Late night conversation, and the guy was chatty, said "Well, you think that gas station situation is irritating.. check this out....."
The example he used was booking an airline ticket. Lets say you decide to take the wife to Vegas, and want to manage the trip with a $5k credit card. Pay down the card to zero, book the flight/room for say $1200 (crazy #, but run with it), planning to have $3800 on the card to "play" with in Vegas. Now, what some airlines will do is Reserve Credit "in case" the person flying "decides at the last minute" to upgrade to First Class. What I describe here is the exact situation that the guy at the Ccard company described (I'm making up the #s, but the dynamics are verbatim), and when I seemed incredulous, he said "Yes, airlines do this all the time, it is common".
This is going on (at least for Canadian residents) very quietly in the backrooms of Ecommerce. Typically people only brush against this in Vegas, when they find out that there is much less than $3800 limit left on their card. If you have a high limit (relative to your spending) card, you'll likely never notice.
I'm nosey (esp. concerning #'s) and happened to follow this trail of breadcrumbs down the rabbit hole. Quite an education. Under Canadian banking law, it appears that a company that you deal with can "reserve credit" on your card, w/o letting you know - basically whenever they feel like it, and using arbitrary amounts.
I can see where this makes sense for a hotel. You book for 2 nights @ $80, so let's say they allow for a few phone calls, and a bit of room service and reserve say $275 to protect themselves. I think that may have been the original intent of these ghostly laws I still don't fully understand.
The airline example is clearly abusive, but apparently, legal in Canada.
One young lady I talked to at the Ccard company immediately commented that she personally found out about the gas station situation when she got out of school with a $500 Ccard. Bought $10 of gas here, $10 there.... and pretty quickly hit her limit.
I find it objectionable that these companies can tie up my credit w/o informing me. If these retail companies reconciled these "credit reserves" instantly a) I never would have stumbled across this, and b) I wouldn't likely be as grumpy about it, even if I did find out. I took the time to politely discuss this practice with the manager of a large gas station - he confirmed that the reconciliation of the "reserve credit" can easily take days normally.
I'm not familiar enough with USA Banking/Retail laws to know if these ghost transactions are going on south of the 49'th.
The Ccard company I deal with is a major one, I just don't feel like naming it in a public forum.
Caveat Emptor.
Rgds, D.