RN Ravi, the Nagaland Governor and the centre's interlocutor for the Naga talks, on Monday, categorically said the central government is "absolutely clear" that there shall be only one national flag and one constitution in the country. The strongly-worded statement comes at a time when the armed Naga group NSCN (IM) is sticking to its demand of a separate Naga flag and constitution as part of a peace deal.