Update k value documentation.

wiki/doc/RealQuantity.md

@@ -15,6 +15,9 @@
 <img alt="D-SI-Image-1.7" width="600" style="border-width:10" src="wiki/doc/D-SI-1.7.PNG" /></a>
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 <img alt="D-SI-Image-1.8" width="600" style="border-width:10" src="wiki/doc/D-SI-1.8.PNG" /></a>
+
+*Remark: It is in the responsibility of the creator of data to provide correct and consitent values for the expanded uncertianty, the coverage factor and the coverage probability. In case of inconsisten data, the value for the coverage factor should be seen as the "point of truth" in the data.*
+
 <img alt="D-SI-Image-1.9" width="600" style="border-width:10" src="wiki/doc/D-SI-1.9.PNG" /></a>
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 <img alt="D-SI-Image-1.10" width="600" style="border-width:10" src="wiki/doc/D-SI-1.10.PNG" /></a>