EXFO FastReporter 2 - Manual (Page 233)

Working with iOLM files
Post Processing Software 223
Modifying Identifier Labels (FR2-FC Mode)
4. Select the identifier from the list of available choices in the Identifiers
table to modify it. You can also rename the identifier by selecting it. As
needed, you can change the corresponding value.
Note: The identifiers label is not editable if the iOLM measurements are selected
with any other type of measurements such as CD or OTDR.
Note: When the Identifier label is selected as None, the values are not editable.