LZ没有好好的看On-line help，上面说的很清楚
PublicAll system users can access the document
PrivateOnly the document owner and subsequent approvers can access the document
PurchasingOnly the document owner, subsequent approvers, and individuals defined as buyers can access the document
HierarchyOnly the document owner, subsequent approvers, and individuals included in the security hierarchy can access the document
Within the installation security hierarchy, you can access only those documents that you or your reporting employees own
