inventory => 'inventory',
invoice => 'invoice_item',
language => 'language',
+ letter => 'letter',
+ letter_draft => 'letter_draft',
makemodel => 'make_model',
notes => 'note',
orderitems => 'order_item',
periodic_invoices_configs => 'periodic_invoices_config',
prices => 'price',
price_factors => 'price_factor',
+ price_rules => 'price_rule',
+ price_rule_items => 'price_rule_item',
pricegroup => 'pricegroup',
printers => 'printer',
project => 'project',