Is my understanding of magnetic variation and declination (for a VOR) correct? AIXM (the XML-based exchange model for AIP by Eurocontrol and european AIS) defines the following properties for a VOR:


codeTypeNorthA code indicating the direction of the "zero bearing" provided by the station, values: "TRUE" (true north) or "MAG" (magnetic north).
valDeclinationThe angular difference between the direction of the "zero bearing" indicated by the station and the direction of the True North.
valMagVarThe local angular difference between the True North and the Magnetic North.
dateMagVarThe year the magnetic variation was measured.


Now say we have a VOR with the following values:

&lt;codeTypeNorth&gt;MAG&lt;/codeTypeNorth&gt;
&lt;valMagVar&gt;0.27&lt;/valMagVar&gt;
&lt;dateMagVar&gt;2018&lt;/dateMagVar&gt;


Am I correct with the following statements?


valMagVar is a positive number, therefore magnetic north is east of true north.
codeTypeNorth is "MAG", therefore the VOR is aligned towards the magnetic north. Since the magnetic variation is +0.27°, the "zero bearing" is equally +0.27° east of true north and therefore the (undeclared) valDeclination must be +0.27° as well.


Please don't comment on the practical relevance of this question. I'm developing and documenting OFMX (a derivative of AIXM) we will use as our future well-defined exchange format for https://openflightmaps.org and I want to be sure to be 100% sure I explain the terms "magnetic variation" and "magnetic declination" accurately in the OFMX documentation.

Thanks a lot for your help!
Since the magnetic variation is +0.27°, the "zero bearing" is equally +0.27° east of true north and therefore the (undeclared) valDeclination must be +0.27° as well.  


You are assuming that the VOR alignment will always be kept bang-up-to-date with the actual measured magnetic variation. Sadly, this is not the case! There is actually a considerable amount of work involved in re-aligning a VOR (it is not just a matter of tweaking a knob!) and re-alignment is only performed rather rarely.

Also note that the terms 'variation' and 'declination' are NOT synonymous in this context - 'variation' refers to the actual measured difference between true north and magnetic north; 'declination' refers to the difference between VOR zero-bearing and true north. These are NOT generally exactly the same.

For example: UK AIP ENR 4.1 (PDF)