| <element name="card" xmlns="http://relaxng.org/ns/structure/1.0"> | |
| <attribute name="name"/> | |
| <attribute name="email"/> | |
| <attribute name="preferredFormat"> | |
| <choice> | |
| <value type="string">html</value> | |
| <value type="string">text</value> | |
| </choice> | |
| </attribute> | |
| </element> |