Three is template tag, unfortunately it is missed in the Help page. here’s the revelvent info:
/**
* Echo the logo if associated in a HTML hCard compliant string.
*
* Accepted option for the $atts property are:
* tag == string -- HTML tag.
* id == string -- The tag id.
* class == string -- The tag class.
* alt == string -- The tag alt text.
* title == string -- The tag title text.
* src == string -- The image source.
* longdesc == string -- URL to document containing text for image long description.
* style == associative array -- Customize an inline stlye tag. Array format key == attribute; value == value.
* before == string -- HTML to output before the logo.
* after == string -- HTML to output after the logo.
* display == string -- Display place holder area or default image or logo. Permitted values are logo, place_holder, default, blank.
* return == TRUE || FALSE -- Return string if set to TRUE instead of echo string.
*
* @param array $atts [optional]
* @return string
*/
getLogoImage( $atts )