The issue or epic is actionable but not yet included in an iteration. It is adequately scoped and sufficiently clear defined for an iteration and no dependency blocks it.

Issues and work that appeared during iteration. If possible those issues should not be solved during iteration but only prepared and organized for future planing

It is clear what work is necessary to realize the work item, how the final result and its components should look like (design in case of features) and if realization is realistically achieved in the turn of 1 iteration

A work item is realized and work is finished, but has not yet been reviewed by the product owner

A work item awaits external dependecy

Create child items (epics, user stories, tasks) in order to substantiate the realization of the work item

Estimate the amount of work by weeks (themes, epics) or story points (user stories)

showcase and try out the product of an iteration/release/initiative

Theme is sufficiently brainstormed and awaits narrowing it down in order to be picked-up for an initiative