Some docstring convention for Reporting Variables

[Loisel]

It would be great to have some inline documentation of reported variables, that can be read via script for output creation. Something along the lines:

...
#§ Liquid fuels from Biomass required in the transport sector
    setNames((dimSums(mselect(vm_demFeSector,all_enty1=c("fepet","fedie"),all_enty="seliqbio",emi_sectors="trans")  ,dim=3,na.rm=T)), "FE|Transport|Liquids|+|Biomass (EJ/yr)"),
...

In this case, the explanation is trivial, but it is not for some (especially emission) variables. This

• makes the documentation of changes easier for the developer, who changes the definition while he changes the code
• can be checked when reviewing PRs
• can be used with, e.g., the IAMC template which requires a definition of the variables
• optionally one could also add some trustlevel of the variable (e.g., low for prices), which is also required by the IAMC template and useful in general when communicating output.

Some people I consider this relevant for @Renato-Rodrigues @LaviniaBaumstark @fschreyer

[Renato-Rodrigues]

I agree, but I think that any solution should be done in a way that this description is also easily saved in a variables metadata file.
csv variables metadata file example:

variable;unit;description
FE|Transport|Liquids|+|Biomass";"EJ/yr";Liquid fuels from Biomass required in the transport sector

I would guess the RSE group is the most competent one to discuss and define what is the best way to add support for this.