{ from => 'purchase_order', to => 'purchase_order', abbr => 'popo' },
{ from => 'sales_order', to => 'purchase_order', abbr => 'sopo' },
{ from => 'purchase_order', to => 'sales_order', abbr => 'poso' },
{ from => 'purchase_order', to => 'purchase_order', abbr => 'popo' },
{ from => 'sales_order', to => 'purchase_order', abbr => 'sopo' },
{ from => 'purchase_order', to => 'sales_order', abbr => 'poso' },