According to the Code of Good Practice in Electoral Matters, however, there must be permanent electoral registers. In fact, permanent registers are standard in CoE member states, with the exception of Bulgaria and Latvia. Furthermore, in the majority of CoE member states, there are centralised voter registers for national elections which allow for cross-checking of nationwide data and for improving data quality. Several countries, for instance Ukraine (2010), Serbia (2012) and, recently, Austria (2018), followed the recommendation to create a national voter register.