The details of the insurance cover under your policy is laid out in the policy wording along with any exceptions and endorsements that have been made to the policy wording by the underwriter.
Whilst the basic cover maybe similar for many types of insurance, the details of the cover can vary considerably from insurer to insurer.
Some policies may include extensions, exceptions or limitations in respect of certain aspects of the cover, whilst others may not. If a policy does not refer to a specific set of circumstances or aspect of the cover the policy is said to be silent on it. This means that there is no specific reference to a particular aspect.
An example of this maybe one policy has an exclusion such as exports to the USA, another policy may be silent on this. Just because a policy is silent on a particular aspect it does not necessarily mean that the cover is in place or otherwise, it simply means that there is no specific mention of that particular aspect and you should check your policy cover or consult with your insurance broker for clarification.