Does 16 really applies to 4 zeros

Please see this link http://help.sap.com/saphelp_nw04/helpdata/en/fc/eb3cf4358411d1829f0000e829fbfe/content.htm

Q] Does 16 really applies to 4 zeros(see output) , & Why should they be multiple of 4 -

Why ? Could you please explain the things .