Which statements are true regarding module and class names?

Module and class names in Puppet have specific naming conventions to ensure clarity and consistency in the codebase. The rule that module and class names must begin with a lowercase letter is a fundamental part of Puppet's naming conventions. This requirement helps distinguish between different components of the Puppet architecture and maintains a uniform system for referencing resources.

In Puppet, module names and class names are typically written in a specific format—lowercase letters enhance readability and ensure that names are easily recognizable as belonging to the Puppet ecosystem. Thus, having them start with a lowercase letter is not just a convention; it is essential for proper identification and function within Puppet manifests.

The other naming conventions state that module and class names can include numbers and underscores, but they cannot start with numbers or underscores. These restrictions prevent ambiguity in naming and ensure that Puppet can interpret these names correctly without confusion. Using 'main' as a name is permissible; however, it is generally reserved for special cases and does not fall under the same category of strict naming conventions. Therefore, focusing on the requirement for starting with a lowercase letter encapsulates an essential aspect of writing valid and effective Puppet code.