[nwbtyedw] Ordinal collections

Objects which have names but could by referred to by number:

Months of the year
Planets.  Though theoretically planets could switch orbits or get destroyed.
Chemical elements (many were named before their proton count was known)
Quark generations
Astronomical spectrographic categories
States by statehood date, picking an order for North and South Dakota.  There will be gaps if there is ever a successful secession.  What should be done if a state splits into two?  Or mergers?  Probably the older one is the one which has the original state capitol, though the new border could go through the building.
Stages of grief

Inspired by how Japanese month names are just numbers.