Explain the scope of Article 19.
The scope of Article 19 is not clearly defined in the provided context. However, from the given information, it can be inferred that Article 19 likely deals with the protection and regulation of various aspects related to the matters listed under Headings 20-31. These include pilgrimages to places outside India, piracies and crimes committed on the high seas or in the air, shipping and navigation, lighthouses, ports, port authorities, airways, aircraft and air navigation, and the carriage of passengers and goods by various modes of transportation.