The two parties consent to assist each other in the surveillance of goods going between the Czechoslovak Socialist Republic and the Soviet Union, letters going between the two countries and from them to capitalist countries, correspondence sent from Czechoslovak or Soviet citizens to people who recently arrived from capitalist countries, the mailing of anti-socialist materials sent through the two nations and mail involving anti-socialist propaganda sent to either country from capitalist countries. Both parties also agree to exchange information on ways subversives use the post to their advantage and how each countryâs officials monitor post suspected of containing ideologically injurious material.