[Google update] 2 thuộc tính mới được thêm bởi Google

1. rel="sponsored"
2. rel="ugc" for user generated content

Source: https://webmasters.googleblog.com/2019/09/evolving-nofollow-new-ways-to-identify.html?m=1&fbclid=IwAR2Sb7XrX-KvEH3xm4RnpJxxN5bDkxusA2Lrn3_qWvSRQ0ukUFWB93U7o28