PTX Structure Question Error in the manual?

I’m reading up on PTX (the PTX 1.4 guide), and I have a question about structure support. In Section 5.3 (page 26) it says, “NOTE: The current version of PTX does not implement structures or unions.”

On the next page, in Section 5.3.4 (the “Structures and Unions” section), it shows how to define structures.

So, are they supported or not?

NOTE: I’m not asking whether nvcc supports compilation of structures written in C. I’m just asking if they’re supported in PTX (i.e. if I hand-coded something in PTX, would it be supported by the JIT engine).