If Silbaby is to be added to TMA as a site it needs to be made 100% clear that it isn't yet widely recognised as ancient. Also, the grounds for including it should be made clear (not an essay or anything, just something simple).
Perhaps Pete could do this and write a short 'Misc' post about the mound. The site category can't really be set as 'artificial mound' until we are sure it is artificial. Until then it should remain uncategorised.
TMA Ed