I seem to have found undocumented character limitations in the unique identifier for script monitors:
Doesn't work: Statistic.this.is.my.identifier: 1
Doesn't work: Statistic.this-is-my-identifier: 1
Works: Statistic.thisismyidentifier: 1
Works: Statistic.this_is_my_identifier: 1
Other than alphanumeric and underscore, what other characters can be used?