::tcl::unsupported is a namespace that contains bits and pieces of Tcl that are experimental , not intended for production code , perhaps useful for debugging and introspecting Tcl , and liable to change or removal without warning .
AMG: If memory serves, once upon a time Tcl had commands called unsupported0, unsupported1, unsupported2, etc. Once they were finalized, they were renamed. For example, I'm pretty sure fcopy used to be known as unsupported0.
I greatly prefer the namespace approach to segregating the unsupported commands.
DKF: Yes, but when unsupported0 was introduced, we didn't have namespaces; I'm pretty sure it came in with the http package, which predated 8.0…