Earlier quoted context omitted.
Clearly the resin identification code and the recycling symbol are causing consumer confusion due to the fact that almost everyone confuses them. The US Society of the Plastics Industry designed their resin identification code in 1988 and made it similar to the recycling symbol which had been in use since 1970, even though many of the plastics thus labeled were not generally recyclable. According to wikipedia[1] they…
The Resin code was designed to help with recycling to determine what can be recycled. It says so in the article you linked. It's the last column on the first chart.
Similar to how the junk food industry is all about telling people to "balance what you eat and what you do", and shrinking portion sizes while also selling "shareable" packs. They are trying to avoid customer ire and/or regulations against them.