Since the true tags are available neither in automatic nor manual annotation, we select 34 Polish words which are often abbreviated 4.1., look up their inflected forms in the Polimorf morphological dictionary (Wolinski et al., 2012), and gather sentences which contain at least one of these words.
we obtain sentences where an abbreviation might have been possible, and consequently acquire labels (the true morphosyntactic tags) for a supervised machine learning algorithm.