| Keyword | Most frequent expressions (number of websites) |
|---|---|
| xhtml | xhtml css (5), valid xhtml (4), html xhtml (2), xhtml valid (2), validate xhtml (1), browser xhtml (1), security xhtml (1), xhtml transitional (1), xu xhtml (1), xhtml xiamen (1), xhtml strict (1), instance xhtml (1), xhtml page (1) |