The term ET (H) is an abbreviation for the job title of Extra-Terrestrial Host, which is a four letter acronym ALIA. An Extra-Terrestrial Host is a person who is responsible for welcoming and accommodating aliens from other planets. They are also responsible for providing them with information about the planet they are visiting and helping them to adjust to their new environment. The job requires a great deal of knowledge about the culture and customs of the alien species, as well as a strong understanding of the language and customs of the host planet.