"Has improper value for" is a predefined property to track input errors for irregular value annotations that was likely caused by type or allowed value restrictions.
en:The authors of a newly created name. For all taxonomic ranks, only for 'comb. nov.' or 'nom. nov.': Author(s) of the basionym (will be displayed in '()', do not enter the parentheses), abbreviated according to authors standard +
The authors of a newly created name. For all taxonomic ranks, only for 'comb. nov.' or 'nom. nov.': Author(s) of the basionym (will be displayed in '()', do not enter the parentheses), abbreviated according to authors standard +