2.1.836 Part 1 Section 18.14.2, ddeItem (DDE Item definition)
a. The standard does not specify length restrictions on @name.
Office restricts @name to not be empty and have a length less than or equal to 255 characters.
b. The standard states that the ole attribute indicates that the DDE item uses OLE.
In Office, the ole attribute specifies that DDE Item is used to provide the name of the data source topic. If set to true, the value of name should be StdDocumentName.