What is an ISWC

The International Standard Musical Work Code (ISWC) identifies a musical work as a unique intangible creation. It relates to the result of an intangible creation of one or more people, regardless of copyright status, distributions or agreements that cover this creation.

The International Standard Musical Work Code (ISWC) for a musical work is usually stored in a database on a computer system. It is divided into three elements, consisting of the letter T (the "prefix element"), followed by nine digits (the "work identifier"), and a numeric check digit.

When an ISWC is written or printed the letters ISWC shall precede it. For ease of reading only, hyphens and dots may be used as separators.

EXAMPLE
ISWC: T-914.170.206-9
ASCENT
Creator(s)
LAZAR VLAD
Duration: 00:02:07
Creator-Id: 00691827604

More information is here

To verify the validity of the ISWC code, you should go to the official website ISWC.