GeoNames Forum

Hey everyone, we just bought the premium service and I am trying to build a hierarchy of geoname places, I am using the hierarchy file to start with, some place (PPL feature code for ex) are not linked to any hierarchy,
for that I am trying to link them to the closest ADM geoname, using a concatenation of country code and admin code ( is that the correct approach ? )
for exemple geoname id 7290691,2654782,2638053
the first is the ADM place and the 2 other are PPL and share the same countrycode/admins code
GB,,ENG,E4,22UD , everything seems working fine, and we seem to end up with the same result as with the hierarchyJson api, but i noticed that for france a lot of the PPL place seems to be linking to the same place name but with feature code ADM,
things that i don't seem to have for other countries (france got more than 33,000 case like that (almost half of the PPL places -> 79560) the second is GB with 7000 ) is that just the way is it or is it a problem?
Second we noticed that some place got admin code part with 00, for exemple 13487606, removing those trailing allow us to find the parent (in this case 2872567), my question is that why are they present, do they represent a specific case ?
Another thing I remarked is that some place got duplicate hierarchy with the same parent, for exemple
geoname id 624197 got twice a hierarchy with the same parent 628281, once the type is ADM the other no hierarchy type,
690904 with his parent 687869 one is type ADM the other adm,
2509951 with his parent 2593113 one is ADM the other is tourism
3437598 with his parent 6255150 one is ADM the other is un m49 region (i guess those ones are legitimate)
4279855 with his parent 4273638 both ADM type (and this one got another ADM hierarchy to 427542

I got in total 1010 case like that, is it something we should be worried about ?
I found around 40,000 geoname entities with exactly the same ascii name, the same feature code and within 0.01 difference for latitude and longitude, would that be duplicates ?
Thanks in advance