Adapt model to SCB: use whitelist instead of blacklist for series codes
(changes made for SCB fetcher)
Context remainder: some providers publish data in languages having "extended" characters (ex Swedish) and having a whitelist of allowed characters is an endless task. Better use a blacklist forbidding:
- 
/because this character is used in URLs - 
(space) because space is often used as a separator 
Edited  by Christophe Benz