This is the official manual for the latest Org-mode release.
If you are following a system like David Allen's GTD to organize your work, one of the “duties” you have is a regular review to make sure that all projects move along. A stuck project is a project that has no defined next actions, so it will never show up in the TODO lists Org mode produces. During the review, you need to identify such projects and define next actions for them.
org-stuck-projectsto define what a stuck project is and how to find it.
You almost certainly will have to configure this view before it will work for you. The built-in default assumes that all your projects are level-2 headlines, and that a project is not stuck if it has at least one entry marked with a TODO keyword TODO or NEXT or NEXTACTION.
Let's assume that you, in your own way of using Org mode, identify projects with a tag PROJECT, and that you use a TODO keyword MAYBE to indicate a project that should not be considered yet. Let's further assume that the TODO keyword DONE marks finished projects, and that NEXT and TODO indicate next actions. The tag @SHOP indicates shopping and is a next action even without the NEXT tag. Finally, if the project contains the special word IGNORE anywhere, it should not be listed either. In this case you would start by identifying eligible projects with a tags/todo match1 ‘+PROJECT/-MAYBE-DONE’, and then check for TODO, NEXT, @SHOP, and IGNORE in the subtree to identify projects that are not stuck. The correct customization for this is
(setq org-stuck-projects '("+PROJECT/-MAYBE-DONE" ("NEXT" "TODO") ("@SHOP") "\\<IGNORE\\>"))
Note that if a project is identified as non-stuck, the subtree of this entry will still be searched for stuck projects.