An alternative to localized repositories of physically secured documents Secure electronic delivery services such as that opened in 2003 by the British Library Document Supply Centre at Boston Spa, allow extended access to copyright material for which access rights have not been granted for open access over the Internet by the copyright holder. These services generally supplement physically restricted and overseen, limited-access reading rooms. Where print access is allowed they supplement physically mailed hard copy and in the case of the British Library printing is restricted to a single copy. Documents can be forwarded but can only be opened on one computer. Similar systems are used in data rooms in the financial services sector although significantly more advanced access control is required including the ability to change rights or even documents in real-time in an important consideration.