Add Untrack A File Without Deleting It as a git til.

README.md

@@ -74,6 +74,7 @@ smart people at [Hashrocket](http://hashrocket.com/).
 - [Staging Stashes Interactively](git/staging-stashes-interactively.md)
 - [Stashing Only Unstaged Changes](git/stashing-only-unstaged-changes.md)
 - [Stashing Untracked Files](git/stashing-untracked-files.md)
+- [Untrack A File Without Deleting It](git/untrack-a-file-without-deleting-it.md)
 - [Verbose Commit Message](git/verbose-commit-message.md)
 - [Whitespace Warnings](git/whitespace-warnings.md)
 

git/untrack-a-file-without-deleting-it.md

@@ -0,0 +1,18 @@
+# Untrack A File Without Deleting It
+
+Generally when I invoke `git rm <filename>`, I do so with the intention of
+removing a file from the project entirely. `git-rm` does exactly that,
+removing the file both from the index and from the working tree.
+
+If you want to untrack a file (remove it from the index), but still have it
+available locally (in the working tree), then you are going to want to use
+the `--cached` flag.
+
+```bash
+$ git rm --cached <filename>
+```
+
+If you do this, you may also consider adding that file to the `.gitignore`
+file.
+
+[source](http://stackoverflow.com/questions/15027873/untrack-and-stop-tracking-files-in-git)