Using Plain English or Dumbing Down?

Apparently the Local Government Association has published a list of words that public bodies should try and not use if they want to communicate effectively with local people. Whilst I can understand why we should avoid some of them ('contestability' and 'place shaping have always been two of my favourites!), others seem perfectly reasonable-are terms such as 'good practise' and 'level playing field' really so arcane?Certainly no worse than old cliches such as 'It is absolutely vital that residents are told how to access services' which is trotted out in the LGA Press Release announcing its'non-word' list!