Music website Genius says it has proof Google is copying its lyrics, displaying them in search results, and driving down traffic to Genius.com.

The evidence is all in the punctuation. Genius has been secretly watermarking lyrics on its website with patterns of apostrophes, which can alternate between the straight and curly single-quote marks.

The watermarked lyrics surfaced on Google's "information panels," which often appear as the first result when you look up a song. Genius even went so far as to make the punctuation marks spell the word "Red-handed" when translated into Morse code.

(Video from Genius)

"Google knowingly displays lyrics that are copied from Genius in search results in order to keep users from leaving Google to go to other sites. They have known about this for two years and it's clearly unfair and anticompetitive," Genius told PCMag in a statement.

Founded in 2009, Genius is a go-to source for song lyrics, especially from hip-hop artists. Sometimes, the artists themselves will supply official song lyrics to Genius. Rap artist Desiigner, for example, gave Genius the definitive lyrics to his hit song "Panda," according to The Wall Street Journal, which broke the news.

In 2016, a Genius software engineer noticed Google had the official Panda version as well, so it began watermarking its song lyrics and has since found more than 100 examples of Google's search engine taking its lyrics. Reportedly, Genius notified Google about the lyrics copying in 2017 and told Google it was violating Genius's terms of service, not to mention antitrust law, the Journal says.

Google blames the issue on third-party licensing partners. "The lyrics displayed in information boxes on Google Search are licensed from a variety of sources and are not scraped from sites on the web," the company said in a statement.

"We take data quality and creator rights very seriously, and hold our licensing partners accountable to the terms of our agreement. We're investigating this issue with our data partners and if we find that partners are not upholding good practices, we will end our agreements," the company added.

Why Google is only investigating the problem now wasn't addressed.

This article originally appeared on PCMag.com.