Sharing Folders
You have the option to share folders with your sub-accounts. These folders will appear with a star in the media database of the sub-accounts. The sub-account will be able to copy content from these shared folders. This allows the sub-account to continue to use the content, even if you have already removed it from the shared folder.
How do I share a folder?
To share a folder, go to "Content" located on the left-side of the navigation bar to access the media database. By right-clicking on the folder, you will have the option to share the folder by choosing "share folder". 
Once you do this the folder will be marked with an astrisk and will be released to all sub-accounts. 
How can to un-share a folder?
If you no longer want to share a folder, you can right-click on the corresponding folder and select "Do not share anymore". Then the sub-accounts will no longer have access to the contents in the folder.
Lock templates
There are slightly different rules for sharing templates which are located in a shared folder. In this case, you have the possibility to lock a template. This allows the sub-account to create content from the template and replace the editable template elements (text & media); however, the template can no longer be transferred to the sub-account's media database. This ensures that the design of a particular template is not changed and that design guidelines are adhered to. If you want to lock a template, the first step is to copy it to an appropriate shared folder and then right-click on the template. A menu will appear, which will give you the option of selected This ensures that the design of a particular template is not changed and therefore design guidelines are adhered to. To lock a template, first copy it to the appropriate shared folder and then right-click on the template. In the appearing menu select "prohibit copying". 
Now the template will be locked, so that it can no longer be copied. However it can still be used by the sub-account to create content. You will be able to tell that the template is locked, by seeing the small lock icon located in the lower right corner. 
Note: Currently it is not possible to share folders only with individual sub-accounts. Any folder which is shared will be visible to all sub-accounts.