From the former Wikipedia page [1], which has now been incorporated in the article on Asemic writing.
Also on the other Voynich wiki [2] - text should be developed in parallel.
False writing systems are artificially constructed alphabets or scripts used (sometimes within the context of a false document) to convey a degree of concealed verisimilitude. Examples of this include alien dialogue in comic strips and graphic novels (such as Alan Moore's The League of Extraordinary Gentlemen [3], and the Valérian and Laureline series [4]). The script in Luigi Serafini's 1981 Codex Seraphinianus may be a false writing system; so perhaps may be the text of the Voynich Manuscript.
There is a certain amount of research on the subject - eg [5].