It's not possible to pursue development of the issue because of other problems.

The hows and whys of the system, concisely and coherently described.

The issue relates to a production system or impacts infrastructure.

Issues that require research and architecture recommendations.

Making it better ... eventually.

Highest priority issues which must be resolved before cutting a new release of the software.

Standalone issues which are easy to fix and make you feel productive. The development equivalent of chocolate chip cookies.

A new feature, made of fairy dust and happiness!

If you're looking for something to do, tackle these issues first.

Describing how and why we do things.

The name says it all.