"Hidden" toolkits and process apps exist for the System artifacts and for anything you mark that way in the Process Center: hidden items do not show in the Process Center lists and in the designer's project chooser unless the user enables Show hidden; they are still installed and used through dependencies.
- How to hide: Process Center > Process Apps (or Toolkits) > open the app > Manage > "Hide this process app / toolkit"; administrators of the app can toggle it. System toolkits (System Data, UI Toolkit, Coaches, Content Management, Dashboards, Case, Process Portal) ship hidden.
- Show hidden: Process Center > Toolkits > the "Show hidden" filter at the top of the list; in the web designer the Toolkits panel has "Show hidden" too. The desktop designer: Toolkits tab > "Show hidden".
- Why: keep the list of a large repository clean (retired apps, internal helper toolkits, the system toolkits), avoid that developers depend on a toolkit that is meant for internal use, and hide vendor-delivered infrastructure.
Hidden is not security: anyone with read access can still open a hidden toolkit after enabling the filter; use the app's Administration permissions (Manage > Administration) to restrict access, and Archive for apps that must no longer be used at all (archived snapshots cannot be installed or opened).
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