Possible to use OR in contextual filter?
I think there is a module for that, Views Contextual Filters OR.


  The module provides a views plugin which modify query to support OR
  conditions for contextual filters.
  
  How does it work? 
  The handler is replaced in views which is used by
  default. A new option will appear in settings page query. If the
  option is enabled the query will be rewritten using operator OR.