Is the SLD “open”? No:
The content is available free of charge to be viewed on screen, copied, printed out for private study and research purposes or for internal circulation within an organisation. To enquire about any other re-use of the data, including in commercial information products and services, please apply for a Click-Use Licence.
This is misleading as the SLD in fact falls outside the scope of the Click-Use Licence, being a “value added” service, so you need to apply for a Value Added Licence.
What are the terms for commercial re-use likely to be? The DCA is still hatching a plan. Indeed, I am being consulted on the issue and will report back in due course. If any aspirant re-users have a view, please comment here or contact me.