The study of separation axioms is notorious for conflicts with naming conventions used.
Steen and Seebach (1970) and various other authors reverse the definition of completely Hausdorff spaces and Urysohn spaces.
Readers of textbooks in topology must be sure to check the definitions used by the author.
This space is completely Hausdorff and Urysohn, but not regular (and thus not Tychonoff).
Examples are non trivial; for details see Steen and Seebach.