BTW: Transistional variants of XHTML and HTML4 should be avoided. These are leftovers from HTML3.2.
https://www.w3.org/TR/xhtml1/dtds.html#a_dtd_XHTML-1.0-Transitional
-> says same as HTML4 Transitional
https://www.w3.org/TR/html401/sgml/loosedtd.html
-> says “Authors should use the Strict DTD when possible”
