For example, in the sentence, "ABC Company, Inc., just announced its newest product." Isn't it a rule that a comma MUST follow "Inc." or "Incorporated" if the formal name of the company includes a comma in its title - in this case after the word "Company." Sorry if this sounds confusing! But that's how I have been marking documents when proofing, yet when I did a search to confirm this, shall I say habit(!), I couldn't find this listed as a comma rule.
A.
Here is what the Gregg Reference Manual says about this:
Do not use a comma to set up expressions like Inc. unless you know that the company prefers to do so.
If you use a comma between the company name and Inc., you also need a comma after it if any other copy follows.