You can configure which HTML elements will remain using the valid_elements, invalid_elements and extended_valid_elements options.
The valid_elements option defines which elements will remain in the edited text when the editor saves.
Example usage:
tinymce.init({
selector: 'textarea', // change this value according to your HTML
valid_elements : 'a[href|target=_blank],strong/b,div[align],br'
});
The invalid_elements option instructs the editor to remove specific elements when TinyMCE executes a cleanup.
Example usage:
tinymce.init({
selector: 'textarea', // change this value according to your HTML
invalid_elements : 'strong,em'
});
The extended_valid_elements option is very similar to valid_elements. The only difference between this option and valid_elements is that this one gets added to the existing rule set.
Example usage:
tinymce.init({
selector: 'textarea', // change this value according to your HTML
extended_valid_elements : 'img[class|src|border=0|alt|title|hspace|vspace|width|height|align|onmouseover|onmouseout|name]'
});
Check out the Tiny documentation for more information: