Wombit refuses some places whatever a rule says, and so does the helper that acts for it as an administrator. The list ships in the open catalog, so it can be read and checked like every rule.
Places it refuses
Nothing in these places is ever offered for removal, never pre-selected and never moved by a cleanup, a filter, the tray or an uninstall.
macOS itself
- /
.DocumentRevisions-V100 - /
.Spotlight-V100 - /
.fseventsd - /
Library/ Apple - /
System - /
bin - /
private/ etc - /
private/ var/ db - /
private/ var/ folders - /
private/ var/ vm - /
sbin - /
usr/ bin - /
usr/ lib - /
usr/ libexec - /
usr/ sbin - /
usr/ share - /
usr/ standalone
Files that sync
- ~/
Box - ~/
Box Sync - ~/
Dropbox* - ~/
Google Drive* - ~/
Library/ CloudStorage - ~/
Library/ Mobile Documents - ~/
My Drive* - ~/
OneDrive*
Keychains
- /
Library/ Keychains - ~/
Library/ Keychains
Libraries their apps manage
- *.fcpbundle
- *.imovielibrary
- *.musiclibrary
- *.photoslibrary
Your folders themselves
- ~
- ~/
.Trash - ~/
Applications - ~/
Desktop - ~/
Documents - ~/
Downloads - ~/
Library - ~/
Library/ Application Support - ~/
Library/ Caches - ~/
Library/ Containers - ~/
Library/ Developer - ~/
Library/ Group Containers - ~/
Library/ Logs - ~/
Library/ Mail - ~/
Library/ Messages - ~/
Movies - ~/
Music - ~/
Pictures - ~/
Public
Inside Documents and Desktop, only items a rule explains can be removed, and none of them start checked.
Anything no rule explains
A folder no rule explains is never offered by a cleanup, a filter, the tray or a review, and never pre-selected. You can still move one to the Trash yourself from its item sheet, after a confirmation that says no rule explains it. Keys, Preferences and other people's home folders stay off even there.
When something does move
Checked again just before each move
The never-touched list, no links on the way, the same kind of item as scanned, and nothing changed in the last five minutes. A problem is reported, never retried.
A cleanup never forces an app to quit
If an item's app is running, the review sheet offers to quit it and leaves its items out until it has quit. Only the uninstaller offers Force Quit, and only after you confirm.
Settings are not caches
Preferences and app state are never part of a cleanup, so nothing resets your apps.
Every run is written down as it happens
One readable log per run, line by line, so even a crash leaves an accurate record of what moved.
The helper stays off until you need it
Items owned by macOS need an administrator. The helper that moves them checks the app's signature, checks every path again and never runs a shell.
The never-touched list ships in the open catalog, next to 243 rules that each have a test. The scan engine, the rules and the command-line tool will be published as open source under Apache-2.0, so anyone can check what a rule matches and why.
How a cleanup runs, and how to put things back, is in Cleanup, the Trash and undo. What the helper is, and when the app asks for it, is in The helper.