The vast majority of MOD's networked computers with Internet connection access the World Wide Web via the Department's Enterprise Gateway Service (EGS). The EGS uses commercial web categorisation software, which places the huge number of websites on the Internet (believed to exceed 100 million) into about 100 categories. MOD then determines which categories can be accessed, and which ones are blocked.
Categories are blocked because they fall into one of the following types:
They contravene the MOD Acceptable Use Policy;
They pose a risk to the technical security of the network, or to broader information security;
They result in excessive consumption of bandwidth or other technical resource, or of staff time.
Also, to safeguard security of MOD networks, MOD does not permit access to sites using mobile code (e.g. Java, Active X).
The attached document, Information Management Protocol 049, is published by the Chief Information Officer on the Defence Intranet, and this explains further detail. A copy of the MOD Acceptable Use Policy (JSP 740) is also attached.