[Jonathan McDowell]

Dear Andrea and others,

1) In the first place, I never liked that rule. Alberto's suggestion
could be implemented in the UCD-analysing software - in other words,
I don't actually bother adding a terminal semicolon to my
 phot.fluxDens
but when you pass it to your search/comparison tool, a trailing
semicolon gets added automatically
 phot.fluxDens;

This is a classic case of wanting to avoid writing 3 lines of code,
and making things annoying for human readability and comprehension.

2) Nevertheless, the rule is what we adopted.

>    Present                       Suggested new
> E | phot.fluxDens               | phot.flux.fluxDens  or:  
> phot.flux.density
> E | phot.fluxDens.sb            | phot.flux.fluxDens.sb  or:  
> phot.flux.density.sb

I agree that the second choices phot.flux.density.* are better.
(Pierre - I don't think losing the fluxDens atom is a problem.)

OK:
> Q | phys.energyDensity          | phys.energy.density

I don't like this, since it's not a mass, it's a ratio.
It's really talking about the composition of the physical
environment (how much baryons, how much photons, etc.)
Maybe phys.composition.massLight (or phys.abund.massLight)

> Q | phys.massToLight            | phys.mass.light

Can you remind me what this means exactly?
Is it a percentage, or e.g. an SNe yield of iron in solar masses?
> Q | phys.massYield              | phys.mass.yield


I don't like suppressing the atmol element. It makes the UCDs
too flat. We could just make them all "at" and explain that "at" includes "atmol".
But if we are willing to make a bigger change,  we can take something
from the work of the DM At/Mol team: some of these items
are species (atmol, particle), some are states (levels),
some are transitions and interactions.
I think it's clear that states and levels are associated with
particles in a way that phys.mass.yield is not, so I would
be in favor of

> Q | phys.atmol                  | suppress

> Q | phys.atmol.element          | phys.species.element
> Q | phys.atmol.excitation       | phys.species.excitation
> Q | phys.atmol.ion              | phys.species.ion    
> S | phys.atmol.ionization       | phys.species.ionization
Q | phys.at.number                       | phys.species.atomicNumber
Q | phys.at.weight                       | phys.species.weight

> Q | phys.atmol.branchingRatio   | phys.transition.branchingRatio
> Q | phys.atmol.coll             | phys.transition.collision
> Q | phys.atmol.crossSection     | phys.transition.crossSection
> Q | phys.atmol.lineShift        | phys.transition.lineShift
> S | phys.atmol.trans            | phys.transition.trans   
Q | phys.at.collStrength                 | phys.transition.collStrength
Q | phys.at.damping                      | phys.transition.damping
Q | phys.at.lande                        | phys.transition.Lande factor
Q | phys.at.oscStrength                  | phys.transition.oscStrength
Q | phys.at.radiationType                | phys.transition.radiationType
Q | phys.at.term                         | phys.transition.term
Q | phys.at.transProb                    | phys.transition.prob
Q | phys.at.wOscStrength                 | phys.transition.wOscStrength

> Q | phys.atmol.parity           | phys.state.parity
> Q | phys.atmol.sweight          | phys.state.sweight
> Q | phys.atmol.configuration    | phys.state.configuration
> Q | phys.atmol.final            | phys.state.final
> Q | phys.atmol.initial          | phys.state.initial
> S | phys.atmol.level            | phys.state.level
> Q | phys.atmol.lifetime         | phys.state.lifetime
Q | phys.at.qn                           | phys.state.qn
Q | phys.at.qn.I                         | phys.state.qn.I


  - Jonathan