The default WYSIWYG editor, for instance, seems to purposely prevent you from entering your ampersands (&) as & which is required for XHTML validation. The way around this is simply to use a different editor; namely, JCE, or the Joomla! Content Editor. JCE will, among other nice features, automatically appropriately encode your typed ampersands, making it easier to ensure your code validates.

One annoying “feature” I’ve encountered with JCE so far, though, is the inability to insert empty alt attributes. Often, particularly in the case of an icon that is more than adequately explained by surrounding text, adding alt text would actually just be at best redundant and at worst confusing to people using screenreaders. However, to validate, you have to include an empty alt attribute (alt=""). JCE doesn’t seem to like this, and will strip your empy alt attribute. I’m sure there is a relatively simple hack to circumvent this.