Is it on topic to ask about requirements such as liquidity, market risk or valuation as specified by the banking authorities?
It's fine to ask questions about regulations, as long as they aren't overly broad, vague, and/or they do not solicit opinion. Regarding the question you asked on the main site that probably provoked this question:
The european [sic] banking authority has published requirements for prudent valuation. What are the main points, and how important is it?
Will it change how derivatives are priced?
The main points and their importance is entirely dependent on your line of business. A better question would have been:
How will the recently-published European requirements for prudent valuation affect derivatives pricing, if at all?