TRANSFER Programming Manual

Item and Package Identification
TRANSFER Objects
40970 Tandem Computers Incorporated 3–5
item, along with other items. You can nest a package within another package, as
shown in Figure 3-4. If a package is nested within another package, the list of
components of the outer package includes the package header item for the nested
package. A package that contains another package is one instance of the general rule
that an item can contain other items.
Figure 3-4. A Package within a Package
Item ID Item ID
Item Item Item
Item IDItem ID
Item
Package Header
Item ID Item ID
Item Item Item
Item IDItem ID
Item
Package Header
Item ID
Item
007
Item and Package
Identification
Every item or package has an identifier (ID) that is unique throughout the network.
This ID always consists of:
A system number that defines the network node where the package or item is
created and ensures uniqueness among IDs on different systems
A local ID that distinguishes among different objects created at a particular node
By using this ID, your application can identify and access any package or item
anywhere in the network without ambiguity.
Your application can also associate a name with an instance or occurrence of an item
saved in a folder. This feature allows correspondents and clients to retrieve an item by
referencing its folder and item names. Different instances of the same item can have
the same name or different names. Multiple instances of a particular item cannot
occur in the same folder, however, even with different names assigned. Section 4
contains more information about named items.