With the Directory Security Feature of DocumentsCorePack for MS CRM 2011, you can prevent users to see certain files from CRM records. Users will not be able to navigate to the associated directory within the file share or SharePoint because DocumentsCorePack will overtake the security for you. In short words: when a user is not able to see the CRM record, he/she will also not be able to see the documents.

For a detailed description, please have a look at the documentation.

However, you have to do additional steps for the Directory Security.

Source: The RIGHT way to enable SSL on MOSS Web Applications

This function allows DocumentsCorePack users to add a document to every created activity (only when using the file explorer or sharepoint setup).

For example, when you send a mail to a marketing lists, an activity will be created for each member of the marketing list.

This extra setting will ensure that the activity also has the document attached in CRM.

This article will show you how to work with this function.