This gets slippery because vertical and horizontal are relative. Let's look at accounting . In most industries, it's a process. Every manufacturer in the widget industry has an accounting department. However, there's also an accounting industry made up of companies that do only accounting and auditing for other companies.
Training is another example.
Many companies have in-house training departments, often with human resources. However, there's also a training industry made up of companies that do only training for other companies. The training companies have accounting departments. So again, there's right or wrong for this part of the report depending on how your business model defines this industry. If you aren't sure, please check with me before you invest too much time here.