u/Ill-Cheesecake-5836

Hey guys! Genuinely curious if anyone knows as I can’t find information online. I think I’ve unconverted perhaps another way to legitimise an article as I haven’t heard this spoken too before, however I wonder if anyone knows what the SML 809751 may be inside the main POLO Ralph Lauren neck tag.
I’m curious not only on the numbers but why it may say SML on a Medium size shirt
(Included other photos to show it is a legit article as I’m not looking to check authenticity but rather ask about that tag)
Thanks!