I have to take a normative view here and propose that you consider the following:
If you got "the second best mark," you may want to familiarize yourself with the various ways academic success is measured at the macro level in order to select the appropriate equivalent for the person or group that is your target.
First there is the matter of the ordinal ranking which seems to imply to me that there is indeed someone ranked higher than you, and if this were the case then that person would be the valedictorian and you would be the salutatorian.
The second thing to that comes to mind is that there is the system of Latin honors typically labeled "cum laude, summa cum laude, and magna cum laude" or "highest honors, high honors, and honors." As far as I know they are typically offered at the undergraduate level upon completion of a program of study and appear to be based on some objective standard such such as crossing a designated overall GPA threshold and/or falling withing the top X percent for a particular grouping. This could yield the result that one year no one in the graduating class met the required GPA level for highest honors and that was an essential criteria that couldn't be salvaged by the addition of a relative criteria such as in the top 10%.
It is up to you to determine if "the second highest mark" is an term of art that has specific meaning in your academic system that goes beyond the plain meaning of the words and instead would more truthfully be represented by some sort of "plus-good" distinction analogous to the aforementioned Latin honors. I say this more to remind myself that when making an equivalent interpretation, always remember to present it on your bona fides in a way that makes sure there is no confusion that arises from it
The interesting thing is that these "honor designations" such as the Latin honor system is more of an enhancement to the degree and are structured to be presented as such. It is worth pointing out also that those whom they identify as the top two students are usually given more work as a result during graduation: Perhaps so everyone gets to witness the penalty for making everyone look bad!
These are some sources: