by darvell » Wed Jun 06, 2012 7:28 pm
It's good that you made the effort to at least search. Now you need to interpret your search results, having found one or more similar trademarks in the registry or in use.
The fact that a registration has expired is no guarantee that is is no longer "in use".
The registration will, however, give you insight to the types of goods or services for which the mark was used, which was the scope of the registered protection.
Changing font or adding symbols to a registered word mark have no impact on whether it violates the brand; the word mark is the most generic protection, theoretically covering ANY instance of the same appearance, sound or meaning on similar goods or services. A "design mark", on the other hand, would be more limited to imitations of the exact appearance of the registered design.
An experienced trademark attorney in your jurisdiction can help you finalize your "clearance opinion" based upon the totality of the circumstances of what you are attempting to accomplish.
I have had clients abandon plans for a name of an electronic product in the USA when they discovered a Norwegian phone company offering a service using a similar name, completely unrelated to the electronic product of the client. It cost them about $15,000 for a complete search and professional opinion regarding the comparative risks of their options.