osm.org/way/225818772/history has ID = 4

What is the meaning of this unusual key? Is this tag needed?
Or maybe can it be expressed in a more typical way that would be easier to understand?
Or maybe this key can and should be documented as useful tagging schema?

osm.org/way/628013775/history has ID = 009000360301008

What is the meaning of this unusual key? Is this tag needed?
Or maybe can it be expressed in a more typical way that would be easier to understand?
Or maybe this key can and should be documented as useful tagging schema?

osm.org/way/628016067/history has ID = 009003770500255

What is the meaning of this unusual key? Is this tag needed?
Or maybe can it be expressed in a more typical way that would be easier to understand?
Or maybe this key can and should be documented as useful tagging schema?

osm.org/way/628015109/history has ID = 009003770500217

What is the meaning of this unusual key? Is this tag needed?
Or maybe can it be expressed in a more typical way that would be easier to understand?
Or maybe this key can and should be documented as useful tagging schema?

osm.org/way/628014018/history has ID = 009000370300900

What is the meaning of this unusual key? Is this tag needed?
Or maybe can it be expressed in a more typical way that would be easier to understand?
Or maybe this key can and should be documented as useful tagging schema?

osm.org/way/25522611/history

mtb:scale=1-2

so, is it 1 or 2? Or is it 1+?

Or maybe 2 is uphil?

name=My Fit Foods
osm.org/node/1249568451

shop=organic ? What kind of products are sold there?

shop tag should contain shop type value - and organic is not one

You can have fair trade shop of various types

shop=greengrocer
shop=cosmetics
shop=grocery
shop=convenience
etc

are all possible. What kind of shop is this one?

Fair trade status can be tagged with fair_trade=yes/fair_trade=only - see osm.wiki/Key:fair_trade