Classical question

What does the 'K' signify in relevance to classical recordings.I think it stands for Kerschel,and although I speak some German the word for opus is not kerschel.
The 'K' stands for Köchel, which is the name of the catalog of Mozart's works and, I assume, the person who cataloged them.
You will also see BWV numbers or Schneider listings for the works of J.S Bach.
Koechel, signified for Mozart's works.
You are very close. It stands for Ludwig von Köchel, who compiled a comprehensive catalog of Mozart's works, assigning each work a number. Today the catalog is known as Köchel's Catalog and the numbers are preceded by "K." to reference the source. For more information, see