In order to qualify for a trademark, the selected term or symbol must not be confusingly similar to an existing trademark registered for the same category of products by another owner. Hence terms within the trademark must not resemble an existing trademark (or a prior application for a trademark) either in their appearance (e.g. spelling, use of a distinctive script) or in the way they sound when spoken.

The trademark offices of many countries, and that of the EU, 'OHIM', operate sophisticated databases allowing literal and phonetic searching of terms from trademark applications and registered trademarks, as well as storing and categorising the symbolic components of these marks.

The term or symbol selected for use as a trademark must also not be descriptive of the goods or services to which it will be applied. The latter restriction is necessary to prevent unreasonable inhibition of public use of the registered terms in relation to the selected categories of words or products. Conversely, entry of a trademark into common public usage over time can result in it eventually being considered as descriptive, thereby losing its capacity for registration.

In many countries long-established commercial use of a term or symbol in association with a company, its products or services, which results in public recognition of the 'trademark' will provide the term or symbol with trademark rights.