whats the rule

tintin
I tend not to follow the rules when it comes to English grammar. I had to look your question up myself to find an answer. Hoping this helps....

"Semicolon

Use a semicolon to join 2 independent clauses when the second clause restates the first or when the two clauses are of equal emphasis.
Road construction in Dallas has hindered travel around town; streets have become covered with bulldozers, trucks, and cones.

Use a semicolon to join 2 independent clauses when the second clause begins with a conjunctive adverb (however, therefore, moreover, furthermore, thus, meanwhile, nonetheless, otherwise) or a transition (in fact, for example, that is, for instance, in addition, in other words, on the other hand, even so).
Terrorism in the United States has become a recent concern; in fact, the concern for America's safety has led to an awareness of global terrorism.

Use a semicolon to join elements of a series when individual items of the series already include commas.
Recent sites of the Olympic Games include Athens, Greece; Salt Lake City, Utah; Sydney, Australia; Nagano, Japan."

http://owl.english.purdue.edu/owl/resource/566/01/

Guidelines for punctuation are not rules of grammar, TTH. You follow the rules of English grammar, you just don't follow the prescriptions.

Oh, thank you JTT. I learned something new today!
......at least I follow some rules