I know that I should be hung from my toe nails and beaten with an organic carrot for not using an HTML validator from the 1st of using Zen-Cart.

But this is now water under the bridge and now that I started using the W3C HTML validator I am struggling with some error (?) messages. For example, in my template's english.php I defined:
PHP Code:
define('BOX_INFORMATION_SHIPPING', 'Shipping & Returns'); 
Yet, the validator claims that this string, despite me using the proper escape code for the ampersand symbol, is erroneous:

# Warning Line 170, Column 134: character "&" is the first character of a delimiter but occurred as data

…6309fd86830a70c4f9638462b">Shipping & Returns</a>

This message may appear in several cases:

* You tried to include the "<" character in your page: you should escape it as "&lt;"
* You used an unescaped ampersand "&": this may be valid in some contexts, but it is recommended to use "&amp;", which is always safe.
* Another possibility is that you forgot to close quotes in a previous tag.
What is going on here? Is this really a problem? If not, how do I turn it off so that I can tell the forest from the trees? I am currently troubleshooting a problem in my page and with scores of "false positives" like this it is almost impossible for me to find the source of the problem.

Thanks!