running tidy with the arguments "-q -e --gnu-emacs true" on the java.xml documentation sources gives the following report 

 ---- begin processing Attr.html
Attr.html:188:2: Warning: <th> attribute "valign" not allowed for HTML5
Attr.html:190:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:193:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:196:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:201:2: Warning: <th> attribute "valign" not allowed for HTML5
Attr.html:203:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:206:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:209:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:214:2: Warning: <th> attribute "valign" not allowed for HTML5
Attr.html:215:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:219:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:222:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:227:2: Warning: <th> attribute "valign" not allowed for HTML5
Attr.html:228:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:232:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:235:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:240:2: Warning: <th> attribute "valign" not allowed for HTML5
Attr.html:241:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:245:2: Warning: <td> attribute "valign" not allowed for HTML5
Attr.html:246:2: Warning: <td> attribute "valign" not allowed for HTML5

Note: The <td> valign Attribute is not supported by HTML5.