i looked into http://sourceforge.net/projects/incrtcl, which contains itcl3.2.1, which uses still the SC_* macros (i got there by clicking on project "incrtcl" on http://www.tcl.tk/software/tcltk/netcvs.html).
i have checked out the version from there, it uses TEA_* macros. jeff, is this TEA2 or TEA3? i got as well tcl.m4 from cvs tcl/tclconfig, which appears to be more recent. in both files, i find not hint whether this is based on TEA2 or TEA3.
itcl 3.2 used TEA1 (which was SC_* macros). The itcl in CVS uses TEA2 (which is TEA_* macros, but unversioned). You should see that the tcl/tclconfig (and related tcl/sampleextension) is TEA3 - it includes a specific TEA_INIT([<VERSION>]) in it (to alleviate more version confusion in the future).
Where is TEA3 documented? Is there a better documentation than the comments of the macros?
It's all the comments in the sample extension and in the macros at this point unfortunately. If you've used TEA before, then it should be easy to move over. One of these years I'll get some time to document this better, but that's not going to happen soon. :/
Jeff