WIP: additional heading specifications.
WIP: additional heading specifications.

alphagov/trade-tariff-backend,bitzesty/trade-tariff-backend,leftees/trade-tariff-backend,leftees/trade-tariff-backend,alphagov/trade-tariff-backend,bitzesty/trade-tariff-backend,bitzesty/trade-tariff-backend,alphagov/trade-tariff-backend,leftees/trade-tariff-backend