In some cases, you may need to add custom data to all documents. In this case, you can use the NodeCustomData or DocumentCustomData (culture specific) fields in the CMS_Tree and CMS_Document database tables, respectively.
These fields are accessible through the following properties of the document (TreeNode):
You can use these values in two ways:
1. You can use them as a single ntext block of text:
TreeNode.NodeCustomData.Value = "my value";
2. You can use them as a collection of custom values that are stored as an XML document:
TreeNode.NodeCustomData["myproperty1"] = "my value 1";
TreeNode.NodeCustomData["myproperty2"] = "my value 2";