Hi No it's not just a US thing with RCI and if you look in the brochure or on their Web-site you can read how much the expected gratuities will be and to who they will be paid. Tips can be paid in advance or on the ship.
p.s. I'm not sure I like it when people use pseudonyms and pseudotowns like yours
Yours Neil and Ida Dow.
As it says on RCI's site:
Q: What are gratuity guidelines for cruises?
A: So that you can thank those who have made your cruise vacation better than you could have imagined, we've developed these gratuity guidelines:
Stateroom attendant: $3.50 USD a day per guest
Dining Room Waiter: $3.50 USD a day per guest
Assistant Waiter: $2.00 USD a day per guest
Headwaiter: $.75 USD a day per guest
Note: These gratuities apply to guests of all ages.
Gratuities for other service personnel are at your discretion. A 15% gratuity will automatically be added to your bar bill or wine check when you are served.
Envelopes for gratuities will be provided in your stateroom on the last night of the cruise. Gratuities may be paid in the following ways:
Pre paid by having them added to your reservation by your booking agent.
Added to your onboard SeaPass account.
Paid in cash at the end of the cruise