In the last week, I've come up against this twice. One restaurant is in Dresden, one is in Prague. Here is the booking form for the Alcron, a one star Michelin restaurant in the Radisson Blu in Prague. It's very clear about its Ts and Cs:

Fee for full cancellation or a reduction of a party size after booking:

Cancellations (including a reduction of a party size) must be confirmed in writing via email to [email protected] and received by the Alcron Restaurant no later than 12.00pm (mid-day), 3 days prior to your reservation date.

In the event that the reservation is not honored in whole by you or is cancelled or is reduced party size with less than the required notice period, the Restaurant will charge EUR50 per person to the credit or debit card that you have provided to secure your reservation.

All credit card information is secure and protected by PCI Data Security Standards.

We are coming by train. I felt uneasy about absolutely knowing the arrangements 3 days in advance, and I did not book due to this policy. I'm glad they were clear and I made my decision accordingly.