They must have borrowed the word for some reason. I have never heard of it... and doesn't have any info

Definition of 'Tombstone' A written advertisement placed by investment bankers in a public offering of a security. It gives basic details about the issue and, in order of importance, the underwriting groups involved in the deal. Investopedia explains 'Tombstone' This advertisement gets its name from its black border and heavy black print. The tombstone provides investors with "bare bones" information, usually directing prospective investors to where they can find a red herring/prospectus. In practice, the tombstone is sometimes made after the issue has been sold. Read more: http://www.investopedia.com/terms/t/tombstone.asp#ixzz1z4qYSoc1

It's just a definition of the word relating to finance. Many English words have multiple definitions. I am unclear about the etymology.