new strains of viruses that "borrow" code directly from other known viruses, to varying degrees; usually identified by a letter, or letters, following the virus family name (for example, VBS.LoveLetter.B, VBS.LoveLetter.C, etc.)
In bookbinding, a word used in reference to the variety or diversity of different bindings or end papers in a printing run or issue. For example, one variant may be a cover on which the book title appears in red, whereas another may be a cover on which the title appears in gold. See also BINDING; END PAPERS; FIRST EDITION; ISSUE; LIBRARY BINDING