> Some HTML elements, such as `<ul>`, `<ol>`, `<table>` and `<select>` have restrictions on what elements can appear inside them, and some elements such as `<li>`, `<tr>`, and `<option>` can only appear inside certain other elements. ``` <table> <blog-post-row></blog-post-row> </table> ``` ``` <table> <tr is="vue:blog-post-row"></tr> </table> ``` > When used on native HTML elements, the value of is must be prefixed with `vue:` in order to be interpreted as a Vue component. This is required to avoid confusion with native customized built-in elements. Reference: https://vuejs.org/guide/essentials/component-basics.html#dom-template-parsing-caveats