It a Play template has parameters, the only 2 valid start of the file are `@(` and `@*`. Everything else I tried resulted in compilation errors.

A Play template can have no parameters, but I don't see how they are really useful. They can only access static elements. It doesn't looks to me like a usual thing, or a good way to use templates.

In general, I would like to try to avoid to mark files from other html template system as Play templates. And that could be the case if we check that the file doesn't start as valid html/xml (starting with something like `<% %>`).

Also HTML is not a strict language at all. The following is a rendered by any browser without any problem.

``` html
test<html><body>test</body></html>
```