The transitional document type allows the used of deprecated tags.
Deprecated
Basically, in the future those pages that use deprecated tags will no longer render. Deprecated tags are being phased out in favor of Cascading Style Sheets for formatting the web page.
lucidity clear, clear-headed.
deprecated tags
I think Tahir mean is clear so the total meaning is clear moon
The only disadvantage used to be that browsers would not support it, but since it became the w3c standard most browsers support xhtml meaning there are no actual disadvantages.
Deprecated features are programming elements, such as functions, methods, or classes, that are no longer recommended for use in a particular programming language or software framework. They may still work, but are considered outdated and may be removed in future versions. Developers are advised to avoid using deprecated features and instead switch to newer, supported alternatives.
Clear.
Clear as glass.
Strict document type
because it is