nmake confclean does not work

When building Qt from source, configure prints a statement:

Qt is now configured for building. Just run nmake.
To reconfigure, run nmake confclean and configure.

I tried "nmake confclean" but it does not work. I got an error instead telling me confclean wouldn't exist.

I used "nmake clean" as a workaround but I am not sure if this command is a, actual replacement.