The definition of anonymity is the quality of being unknown.
An author who is not releasing his name is an example of maintaining of someone maintaining anonymity.
the condition or fact of being anonymous
- The quality or state of being unknown or unacknowledged.
- One that is unknown or unacknowledged.
(countable and uncountable, plural anonymities)
From Ancient Greek ἀνωνυμία (anonymia) ("without a name" or "namelessness").