Alnica argues for a distinction between two types of overt dogwhistles. The first, which Alnica calls sense codes, are overt dogwhistles that carry at least two plausible significances, at least one of which is innocent and generally known and thus available to run cover for its other more sinister significance known only to so-called “insiders.”

The second, which Alnica calls nonsense codes, carry no such generally known significance. In this case, it is the general appearance of insignificance that runs cover for the more sinister significance available to insiders. Alnica argues that while this distinction may appear rather minor, it in fact carries an important consequence for the possible roles overt dogwhistles can play in the spread of harmful ideology. In particular, Alnica will show that only sense codes can recruit new members to the insider group. Nonsense codes, by contrast, can only ever allow fellow existing insiders to recognise one another.