Rocket Validator looks for accesibility violations on your pages using the axe-core accessibility engine, hosted on our own servers and integrated into our web crawler. You don't need to buy an additional license, everything's already included in your Pro account at Rocket Validator.
A11Y check: All th elements and elements with role='columnheader' or role='rowheader' must have data cells they describe
Accessibility rule: Data table markup can be tedious and confusing. Markup tables semantically and with the correct header structure. Screen readers have features to ease table navigation, but tables must be marked up accurately for these features to work correctly.