Designers corner is a sub-domain specially separated for the designers,
where the instructions of play are provided clearly and there is no
confusion as to what the job is and how to do it.
Designers corner has no wish to teach anybody how to do their job, it only ensures that the job is done correctly, compatibly and fairly.
The css verifyer is set according to cascading style sheet regulations (CSS Level 2.1), set out by W3c.