- All Opera versions, IE4+, and Netscape up to version 6.0 support the original
PLAINTEXT specification which did not accept a closing tag.
- Internet Explorer up to version 3, Netscape 6.1+ and all Mosaic versions
provide for a closing tag. A closing tag would allow placement in regions
other than the end of a HTML document.
Plain PLAINTEXT element, with nested B element (It should be fairly evident if parsing stops beyond the end tag):
plaintext NESTED BOLD ELEMENT, character entity: & plaintext