Today's computer age makes it easy to print your own warning cards in most (if not all) languages.

A friend, who frequently travels in Europe on business, prints her own cards in the language(s) of destination(s). Friend uses the same method in US.

I noticed a postive difference when the server was given the card and friend explained the printed info, "I have severe food allergies. Under no circumstances can I eat: xxx, xxxx, xxx,"

The card reinforces her verbal explanation and makes the server realize she is not simply whining about too much pepper.