You specify the ENTRYTYPE parameter to indicate whether you want to update an existing list entry, create a new one, or to indicate that a new list entry is to be created only if an existing one (with the attributes you have specified) cannot be found:

ENTRYTYPE=OLD

Indicates that the write request is to be performed only if the specified target list entry already exists.

ENTRYTYPE=NEW

Indicates that a new list entry is to be created.

ENTRYTYPE=ANY

Indicates that the WRITE request should be performed as follows:

• If a list entry with the specified attributes exists already, it is to be updated.
• If a list entry with the specified attributes does not exist, a new list entry is to be created.