Existing grammar frameworks do not work out particularly well for controlled
natural languages (CNL), especially if they are to be used in predictive
editors. I introduce in this paper a new grammar notation, called Codeco, which
is designed specifically for CNLs and predictive editors. Two different parsers
have been implemented and a large subset of Attempto Controlled English (ACE)
has been represented in Codeco. The results show that Codeco is practical,
adequate and efficient