Function valid_identifier

Verifies tracker identifier

Tests if a given input string is a valid tracker identifier. A valid identifier contains only upper and lower case letters, digits and underscore.

A conditionally valid identifier also contains dash. This is used for legacy reasons but is discouraged for new trackers.

Input:

• identifier: A string to test.

Ouput:

• valid: True if the string is a valid identifier.

• conditional: True if the string is a conditionally valid identifier.