Legal Question in Intellectual Property in California

The standard that the United States Patent and Trademark Office ("USPTO" uses to evaluate whether a certain trademark can be registered is that the mark is not "confusingly similar" to an existing registered mark. If you have a word mark registration and someone comes along and tries to register the same word but just uses a hyphen (or spells it a different way) then that new application will be refused. This typically holds true by international class...but sometimes can hold true across classes.

I agree. A change as trivial as additional punctuation, or changing "and" to "&" or "One" to "1" is almost assuredly not going to create a separate trademark or insulate a competitor from an infringement action (assuming the products or services are in the same or closely related international classes.