>Ah, but in all these cases the user doesn't see the syntax at all - the user selects a piece of text, clicks the button and the tag is applied to the text, and it's immediately rendered in HTML; tags are not visible at all. Only for those who are so inclined, some html source editing is still available but then the user is left with whatever they made - if it's unreadable, or won't display properly, they can only blame themselves. And that's how it works on practically any forum today.

Yes, if there would be that, we would control the input.

But, I need to validate on the output as well as I have a lot of content and even if I would run a procedure to update non standard Html from the database, I would still want to make sure it is ok at runtime.

On that, Rick Strahl provided a nice reference to an utility which can be used.

>I know that what we have here is a plain old textarea and what I'm describing is html editing, which is conceptually different in several ways. Mentioned this just because I thought it would be a cool feature to have, new or unaccustomed users would have an intuitive interface (i.e. what they're already used to) and you wouldn't have much work to do, as the code for it is widely available in various open source platforms.

But, this will come. It is also in my list.