Mahara 1.6 generates this code out of `htdocs/theme/raw/templates/header/head.tpl` and/or `htdocs/theme/default/templates/header/head.tpl`:
<link rel="image_src" href="{$sitelogo}" />
Since the DOCTYPE specified HTML 4.01, this is technically invalid. It should either not use the short tag or (my preference) change the doctype to HTML5.
Mahara 1.6 generates this code out of `htdocs/ theme/raw/ templates/ header/ head.tpl` and/or `htdocs/ theme/default/ templates/ header/ head.tpl` :
<link rel="image_src" href="{$sitelogo}" />
Since the DOCTYPE specified HTML 4.01, this is technically invalid. It should either not use the short tag or (my preference) change the doctype to HTML5.