Red, it's ok, I shan't mind waiting :)
I reckon I know why you are a bit confused, and I have checked my info and found I was, too, a bit :).
While WHO charts do exist in Norway, the Norwegian charts in general use are indeed based on data from the Bergen Growth Study which goes from birth to age 19. The subjects are solely Norwegian, with no attempt at ensuring they were all bf, with no early solids or formula. The centiles which come from this study for babies under six months are more or less identical to the centiles shown on the WHO charts, but after six months, the centiles for height and weight are gradually higher than the WHO charts. This means that, say, 'Bergen' babies aged one year on the 50th centile are heavier than babies elsewhere also on the 50th centile.
There is no conspiracy in Norway, or in the UK, to skew the data (I think this is what you were suggesting???) or mis-represent anything.
WHO (and UK-WHO) charts show the physiological growth of babies wholly or predominantly breastfed - how 'nature' expects babies to grow, from a full range of ethnicities. The 'Bergen' data shows how babies actually grow, and also reflects the larger-at-birth size of Norwegian babies, who 'nature' would also expect to be bigger at age 1 year.
I think this resolves the issue - if BabyRed's growth curve seemed to change, it was because on one chart he was being plotted with Norwegian babies not necessarily breastfed (though most would have had a lot of breastmilk) and in the UK he was being plotted alongside babies all over the world, if you get me.
However, there is no significant difference below six months, which interestingly is also the case comparing the current charts in the UK with the charts in use in the UK before 2009, which came from a dataset called UK90, which did not differentiate between bf/ff/mixed. It's only after six months or so that babies on the current charts start to 'drift' away from the UK90 centiles.