[Tagging] RFD pipeline sub tag substance

[Rainer Fügenstein]

> I'd like to repeat once again that "substance" doesn't seem to be a nice
> key descriptor for values like ...

during the draft stage, I (we) couldn't come up with an expression that
covered everything that might one day be transported in a pipeline.

content ... too static
medium ... too spooky
product ... is sewage a product?
type ... too generic and already in use

and what exactly is a neutron bean?

etc.

a native english speaker may come up with a proper expression, but I'd
better not change this key once again.

>> Oh.. 'multiphase' is a mixture of gas, fuel and water as it comes out
>> of some well heads
> if this is the proper term used for pipelines, then this would be the
> right one,

yes, "multiphase" is a term used in the oil&gas industry for exactly this,
uhm, substance.

cu