X’s law reformulated as “Usenet Rule #4”:
“Any off-topic mention of Y will cause the thread it is mentioned in to come to an irrelevant and off-topic end very soon; every thread on UseNet has a constantly-increasing probability to contain such a mention”.
What is X?
The person referred to in the law goes into the connect.

Axis Powers Hetalia is a  popular anime showing an allegorical tale of the history of the world, especially during World War II, with anthropomorphizations of different countries and the various stereotypes associated with them.
In the show, Italy and X were briefly raised together as infants, before Grandpa Rome took Italy away to live with him for the Renaissance period. By the time Italy returned to his place of birth, the other children had become bullies to him.
Italy was claimed by Austria, on the behalf of X, after a period of war. The two children lived together in the same household, X harboring a crush on Italy, who he believed to be a girl (don’t ask its the Japs). However, life soon became uneasy. X  asked Italy to become a part of his empire, which he refused, remembering what had  happened to his grandfather. X left,  leaving  Austria, Hungary, and Italy behind.
Eventually, after the long period of war (almost three decades), X was believed to have died. In a scrapped strip, France broke the news to a teenage Italy that X was no more.
What is X?
X goes into the connect.
X was one of the leaders of the Indian National Congress and one of the founding fathers of the Republic of India. He is known to be a social leader of India who played an unparalleled role in the country’s struggle for independence and guided its integration. He took charge of the task to forge a united India from the British colonial provinces and more than five hundred self-governing princely states. Often known as the “Y of India“(because of Y’s similar role in the unification of his own country), he is also remembered as the “Patron Saint” of India’s civil servants for establishing modern all-India services.
Who are X and Y?
Y goes into the connect.
What is the connect?