This content is said to be published a while back (a couple of years ago or more) in the Google Search developer resources.
Note: After seroundtable.com published this post, Google removed the docs for the blogger SEO practices.
Fortunately, a screenshot was taken. See below:
One person commented on seroundtable.com’s post that the said guideline was only removed for the English version and that the guideline for other languages is still available. See the screenshot below:
What do we think about it?
Whatever reason Google may have for hiding or removing it, the guideline is very sound. Creating great content and making sure readers and crawlers would find it has been the foundations of SEO. Therefore, let us apply it to whatever we do.