Can I use a comparison mask for NCM RUNNING VS STARTUP configurations?

Document ID : KB000109095
Last Modified Date : 02/08/2018
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we are using the NCM config backup for startup and running configuration comparisons but are still getting "STARTUP AND RUNNING CONFIGURATIONS ARE DIFFERENT" alarms based on a part of the startup configuration that is supposed to be masked by the mask configuration.

Is the NCM comparison mask taken into account for running vs. startup or for running vs. running comparison only?
Startup and running configs are only compared with each other. The mask only works for host configurations of the running configuration.
Additional Information:
For more information on Device Family Comparison Masks, see:

The Comparison Mask is a list of regular expressions that conceal device configuration content during a comparison with a historical configuration.
Any line in the device configuration file that matches a regular expression in the Comparison Mask is ignored during comparisons of configuration files. 
Network Configuration Manager provides a list of predefined masks that are displayed in the window next to Comparison Mask.