I think he is referring about lowercase text in the hyperlink, does the hyperlink text match the actual page text i.e www.yourwebsite.com/page2.html and the hyper link is trying to forward it to www.yourwebsite/Page2.html example:-
Look at the two links below, only one of them will work
http://www.cableforum.co.uk/board/index.php
http://www.cableforum.co.uk/Board/index.php
That is what I assume SMHarman is talking about.