[Tagging] RFD pipeline sub tag substance

[althio]

John Willis <johnw at mac.com> wrote:

> Substance=gas
> Substance:detailed:multiphase_gas
> Substance:state=multi

That is not coherent. Do you mean that (substance=gas) is for mainly
gas or gas-only?
If it is gas only (substance=gas), it can be multiple gaseous
products. But it is not multiphase.
And then state=gas, not state=multi.


>> substance=multi is about OK as a shorthand. Using multi -- instead of
>> actual values -- may also imply you are not going to give further
>> detailed tagging.
>> substance=multiphase is really awkward.
>
> I think it would be substance:detailed:multiphase_gas for a particular item, not as a general description.
>
> Otherwise, it is multi for the state or matter... Right?

Right, multi for state. My previous proposals were:

1.
substance:state = * or substance:phase = *
values limited to list eg.: gas, liquid, solid (cables), slurry
(=liquid+solid particles), multi (=multiphase, mostly gas and liquid,
possibly particles)

2.
I advocated for
phase/state=multi or multiphase
substance=[multi-valued] eg. substance=oil;gas;water