Does the SELECT statement count into DML? Looking at the name Data Manipulation Language (DML) I would assume, that all contained statements are actually for manipulating data.

As far as I know the SELECT statement can only be used to query data, not change it. (Not taking INSERT ... SELECT into account here.)

So is SELECT part of DML and if so, why?
You do manipulate and restrict data: GROUP BY, ORDER BY, TOP, JOIN, lock hints, etc

You just don't change the database state when you do.

It boils down to whether you read "manipulate" to include "change state"