Hi. I'm Matt Karpowich, aka Monzo of the Obscure Transformers Website. I've been keeping a Transformers-related trademark file for my own convenience for some time. What follows is an elaborate, hopefully informative - well, bunch 'o stuff. With luck, it won't be needlessly confusing.
I get all of my trademark application data from official documents obtained via the US government's online trademark database. The government defines a trademark as:
"Any word, name, symbol or device, or any combination thereof, used or intended to be used by a person to identify and distinguish his goods from those manufactured or sold by others and to indicate the source of those goods. In short, a trademark is a brand name."
Every modern Transformer name, faction, and (most) subgroups are either trademarks or registered trademarks. One foolproof indication of a trademark being registered would be an "®" symbol gracing the package of a toy that uses it instead of a "™" symbol. The "™" symbol merely indicates that a given word, symbol, etc. is being used as a trademark, and is intended to give notice to others that the user is asserting trademark rights.
A registered trademark has been examined and approved as an appropriate trademark by the federal government. Federal registration includes notice to the public of the registrant's claim of ownership of the mark, a legal presumption of ownership nationwide, and exclusive rights to the mark for certain goods and services. A registered trademark is easier to enforce against infringers than a common-law trademark, but costs money to obtain, and must be renewed with proof of use of the trademark every few years. If the owner does not continuously use the trademark, then it will expire.
Since early into the toyline, Hasbro has been applying Transformers trademarks for registration. However, applications were evidently sporadic during the '80s, given how few from that era are in the online database. In these modern lawsuit-happy times, companies are much more likely to sue over trademark infringement, so Hasbro has been applying for names it has used or intends to use more often than in the past.
This list covers not only trademarks that Hasbro has applied for or has ownership of, but marks they have previously applied for or had registered which were subsequently either abandoned during the registration process or fell into disuse and were cancelled. Furthermore, trademarks of companies that have been absorbed into the Hasbro conglomerate are considered properties of Hasbro in this list.
Non-Transformer trademarks owned by Hasbro are included in these listings because, hypothetically, many of them could be used on Transformers toys with little trouble, especially if the Goods and Services are vague enough (such as "action figures"). Why include trademarks whose Goods and Services are not explicitly action figure-related, then? Because, although Hasbro may not be able to use those registered trademarks across different types of goods, their ownership of those marks prevents any other company from using the word for toys. This means that obtaining one of those trademarks for Transformers would be as simple as re-applying for it under a different set of Goods and Services. Whether they would desire to do this or not is another matter entirely.
Current and previous Hasbro subsidaries include, but are not limited to: Cap Toys, Kenner, Larami Limited, Lewis Galoob Toys, Milton Bradley, OddzOn, Parker Brothers, Playskool, Tiger Electronics, Tonka, TSR, and Wizards of the Coast.