Firmware maturity levels - what does 'N' means?

[FNT_Learner]

Hello guys,

is there anyone who knows the exact meaning about letters added after fortios version. for example 6.4.9N . I already know there are 3 letters, (F,N,M). M is a tag indicates "Mature", F for "Feature". but there is no document about letter 'N'. I would be happy if anyone can give me a correct idea about it. 

thanks. 

[FNT_Learner]

So what do you mean by "Neutral"? what is the exact meaning of this word in terms of Maturity firmware level?

[ozkanaltas]

I said Neutral or like that. Because I don't know exactly what the meaning of "N" is. Maybe the meaning of "N" is not supported by the Maturity Level.

I think just one thing is important here. The maturity level starts from 6.4.10, that's all. Versions older than 6.4.10 are not evaluated with maturity level.