Set off of loss under same head: intra-head loss adjustment allowed, subject to defined statutory exceptions. Losses from one source may be set off against income from another source within the same head of income, except where statutory exclusions apply. Specified exclusions include speculation business losses (only against other speculation income), race horse activity losses (confined to that activity), long term capital losses (not set off against short term capital gains), specified business losses (only against profits of specified businesses), losses from exempt sources (not allowable), and lottery or wagering losses (not allowable against any other income). Anti stripping rules have been extended to cover bonus and dividend stripping.