Requires little time and effort if you have requisite knowledge. Related to but different from "beginner-friendly".

Requires little knowledge of Mailman internals to work on. Related to, but different from, "easy".

User questions with no changes required in the Code

Related to the REST protocol use for communication with the Mailman core. You probably should not use this; such issues usually are specific to mailmanclient.

The UI makes things hard to do, or doesn't provide an operation.

Internationalization, including words that should be translated but aren't (bug) and languages that aren't available at all (wishlist).

Bug

Enhancement Requests

Changes need to implemented in Mailman core, mailmanclient or another project before this can be fixed

Appearance, usually related to Django templates and widget choice.

Request for enhancement. If the requested change doesn't improve conformance of Mailman to documentation or to the usual "implied warranties" of software (doesn't crash, doesn't destroy your data, doesn't spill coffee on your cat, etc), you should add this label.

Missing or incorrect tests (not test failures -- report those with the relevant functionality tag). These issues are often "easy" and/or "beginner-friendly".

This task can be repeated by many people and still be useful (e.g. adding tests), so don't close it without discussion.

Any time the software allows you to do something you don't think you should be able to do, including crashing the program.

Project should not be released without a fix for this issue. *This label is property of the project lead. Do not use it without discussing with a project lead.*

Report is incomplete or not reproducible and a query has been sent to the OP. (If you tried the OP and didn't get a response, close as either INVALID or WONTFIX.)