I honestly think it's a very informative article, clearly SQL Server doesn't adhere to the standard (whichever one you choose) but I'm not aware of any RDBMS that does so I was curious as to whether there was one.

There's lots of amazing databases around, each has their own quirks and as the gp says it's generally difficult to drop in replacements due to those quirks. There's a few listed in the article for SQL Server I'm sure anyone could easily find where others deviate from the spec too. But anyway getting back to what you said:

> He is giving examples of violating the standard

That's absolutely true and it's something every other RDBMS does.