Leaving passwd_override File Fields Blank
If you do not want to override an item in the passwd_override file, leave its field blank, separating each blank field with a : (colon). You must enter one of the keyfields, however, to identify the principal or group for which you are creating overrides. For example, an entry to override the home directory for the account identified by mozart looks like this:
mozart:::::/aria/wolfgang:
You must enter the colons that are associated with any blank trailing fields. In the preceding example, a colon is required for the shell field, which is the remaining field after the home directory field.