Symbols exclusively made up of generic and/or descriptive elements cannot be protected as trademarks because they lack distinctiveness, and, therefore, no economic agent can own them.

However, like with all rules, there is an exception. A trademark can be used to protect a symbol which lacks distinctiveness providing the applicant can demonstrate that the trademark has acquired sufficient distinctive capacity through use. This is known as "secondary meaning" and is provided for in article 238, No. 3 of the Intellectual Property Code.

Extended use of a trademark in the market for products or services which alludes to a certain type, quality, quantity, geographical origin or any other generic characteristic, may demonstrate that it meets its distinctive function if, in general, consumers can perfectly identify its business origin.

The specific case of the EXPRESS MAIL trademark, whose international registration is currently protected in Portugal, was initially rejected because of lack of distinctiveness since its meaning alluded to “an expression frequently used in normal language or in the common habits of the market".

However, United States Postal Service, owner of the aforementioned trademark, managed to demonstrate that the expression Express Mail had acquired distinctiveness through use.

In order to demonstrate that the trademark had contained "secondary meaning", the applicant or owner of the trademark must demonstrate the following:

- extended use of the trademark in question,

- dissemination of the trademark through advertising in printed media, sponsorship of cultural or social events etc,

- a significant turnover associated with the trademark

In this regard, and bearing in mind the lack of objective legal criteria, market studies can be considered to test consumer knowledge of the trademark in question.

In short, all these aspects led to the conclusion that the general public recognises a trademark and associates it with a specific business origin, irrespective of its original and current meaning.