I don't immediately see this addressed here, so: on my Hilton Amex, I see an offer of $10 back on a Hilton gift card of at least $50. The terms in the email say "The Hilton Gift Card may be used only at Hilton Hotels and properties worldwide that accept American Express Cards." The purchase page has "The Hilton Gift Card is accepted at all hotels within the Hilton Portfolio. " Would this mean all Hilton family brands, or only flagship Hiltons? I'm looking at a stay at an HGI.