Understanding 'SIL' Mark on Dress Studs: What Does It Mean?

Question
Dear Thomas, I have inherited a set of dress studs. They are marked SIL. What does that mean.

Answer
Dear Jan,

Thank you for this question.  Unfortunately, the answer will be not directly to the meaning since the mark SIL is not a recognized mark for metal quality and if a maker's mark, that is a rabbit trail to research.

The following website provides listings of more modern Danish marks for sterling silver. If you may have thought the SIL to represent silver the marking is not correct. Simply silver could be any mix of unknown quality of fine silver with other metals. Sterling silver is defined by the name "sterling", being recognized universally as 0.925 pure silver and the remainder other metals, generally copper, 0.075 by weight.  The mark is generally 925S in Danish goods along with a three towers assay mark on certain goods assayed as truthfully marked.

http://www.925-1000.com/dm_General.html

Jan, I do hope this information will be of some assistance, even if the SIL remains an unknown.

God Bless and Peace.     Thomas.