Not all trademarks receive the same level of protection. Some marks may be denied court protection altogether, while others may be granted only limited registration and protection. However, even when a mark is capable of protection by the courts, and can be registered on the Principal Register, there still exists a continuum of protection available. The protection afforded is directly linked to the legal strength of the trademark.
Generally speaking, trademarks with higher levels of protection permit the owner to enforce through the court system their exclusive right to use their mark against a broader variety of similar marks, for a broader variety of goods or services. Thus, when you are selecting a mark, you will want to consider choosing one that will provide the most legal strength for your business.
The classification system of trademark strength described below is widely recognized as distinguishing the different levels of distinctiveness that a trademark can obtain. Generally speaking, the more distinctive the mark, the stronger the protection available. The major exception to this is dilution of a mark, i.e. weakening of a mark due to widespread use of closely-related marks.
The continuum of distinctiveness in trademark law is also known as the continuum of descriptiveness, because the contiuum captures how closely related the word or symbol being used as a trademark is to the service or good sold.
In sum, legal strength can be assessed on the dimension of descriptiveness (below) and how diluted or widespread the word or symbol is used. Note, the classification system below was originally developed for the purpose of classifying lingual marks, but has since been viewed as a model for trademark protection in non-lingual marks as well. Nonetheless, the following definitions continue to be cast largely in terms of lingual marks. Analogies to non-lingual marks should be made whenever they fit.
See Also...
Continuum of Destinctiveness