Substance of Idioms: Perennial Problems, Lack of Data or Theory?

In the following remarks, some of the major recurrent problems of the phenomenon of the idiom, or, alternatively, phraseme and, partly, of its discipline, i. e. idiomatics or phraseology, will be taken up. In so doing, the roots of these problems will be sought. A brief analysis of some cases and of how dictionaries deal with idioms is followed by a restatement of major aspects of the discipline and a list of desiderata.