Good idea, thanks for the suggestion.
In the following beta : https://dl.dropboxusercontent.com/u/13064071/ca/plantuml.jar
You can have:
@startuml
package foo1 <<Card>> {
class Class1
}
@enduml
If someone find a better syntax keyword than "Card", please post.
About Creole, we will on day publish a version that allows Creole everywhere. But we are doing regression test right now, because this new parser (the Creole one) could create unexpected changes.
Anyway, we will publish a beta version when this will be ready for users' testing.
Thanks,