Mongodb -- Database -- Naming Conventions.

Database Naming Conventions:

The naming for database is case insensitive. Since you can use any letter, any special character for creating a database. But for deployments of MongoDB on certain platforms, there are some restrictions.

Windows :

Do not use following characters in naming a database name for MongoDB deployment  on windows.

/\. "$*<>:|?

also there should be no "NULL" characters in database names.