The richness of variant terminology is such that it can enhance vocabulary, as in the case of synonyms, or can complicate information retrieval, as in the case of variant spellings. Variant terminology is defined as consisting of relational variants such as synonyms and quasisynonyms and format variants such as spelling and capitalization. Format variants more specifically include British and American spelling variants, misspellings, transliteration variants, and capitalization. Many varieties of English spelling, particularly British and American spelling variants, often hinder retrieval of information. A “variant terminology switching (VTS)” system is proposed to provide computer-aided British to American spellings and vice versa. This system is also adaptable to recognize common misspellings and to regularize the spelling of computerized input or output for specific audiences. The solutions to problems raised by variant terminology can come about by utilizing techniques brought out in this paper. Development of authorities such as dictionaries and thesauri should result in more standardized terminology. Actual examples of computer-aided lexicography at the NASA Center for AeroSpace Information are also presented and show how computer access to variants enhances terminology understanding and retrieval by giving structure to varieties of variant terminology. The reader will find a sweeping treatment of the topic “variant terminology” as well as an extensive bibliography on the subject.