In biology or medicine, a multi-entry key is an identification key

Identification key

In biology, an identification key is a printed or computer-aided device that aids the identification of biological entities, such as plants, animals, fossils, microorganisms, and pollen grains...

 that allows the free choice of characters only in the first step. Whereas in a typical multi-access key

Multi-access key

In biology or medicine, a multi-access key is an identification key which overcomes the problem of the more traditional single-access keys of requiring a fixed sequence of identification steps. A multi-access key enables the user to freely choose the set and characteristics that are convenient to...

 the choice of characters used for identification can be repeated multiple times (reducing the number of remaining taxa each time), in literally multi-entry keys only the first step involves a free choice of characters. Examples for multi-entry keys are the keys created by the FRIDA

Frida

Frida is a 2002 biographical film which depicts the professional and private life of the surrealist Mexican painter Frida Kahlo. It stars Salma Hayek in her Academy Award nominated portrayal as Kahlo and Alfred Molina as her husband, Diego Rivera....

software, where a single step of selecting one or multiple criteria is followed by a dichotomous key for the species remaining after this step. Several multi-entry keys are available in the pages of project Dryades, section identification tools.