Taxonomy in NeetoInvoice lets you set custom invoice labels so the product uses your business's language instead of default terms. Currently it relabels the Notes section on your invoices, and the change applies globally, so every invoice shows the new label.
If Notes feels too generic, rename it to Terms and Conditions, Payment Instructions, or Project Scope, depending on what you put there. Admins change the label from Taxonomy under General in the Admin panel. Clients then see a heading that matches the content, which makes your invoices easier to read.