diff --git a/Library/Homebrew/cmd/install.rb b/Library/Homebrew/cmd/install.rb
index af6772518d..7b6be43d43 100644
--- a/Library/Homebrew/cmd/install.rb
+++ b/Library/Homebrew/cmd/install.rb
@@ -37,7 +37,8 @@ module Homebrew
                           "or a shell inside the temporary build directory."
       switch "-f", "--force",
              description: "Install formulae without checking for previously installed keg-only or " \
-                          "non-migrated versions. Overwrite existing files when installing casks."
+                          "non-migrated versions. When installing casks, overwrite existing files "\
+                          "(binaries and symlinks are excluded, unless originally from the same cask)."
       switch "-v", "--verbose",
              description: "Print the verification and postinstall steps."
       [
diff --git a/Library/Homebrew/cmd/upgrade.rb b/Library/Homebrew/cmd/upgrade.rb
index bdc1e8e95d..04839b7123 100644
--- a/Library/Homebrew/cmd/upgrade.rb
+++ b/Library/Homebrew/cmd/upgrade.rb
@@ -32,7 +32,8 @@ module Homebrew
                           "or a shell inside the temporary build directory."
       switch "-f", "--force",
              description: "Install formulae without checking for previously installed keg-only or "\
-                          "non-migrated versions. Overwrite existing files when installing casks."
+                          "non-migrated versions. When installing casks, overwrite existing files "\
+                          "(binaries and symlinks are excluded, unless originally from the same cask)."
       switch "-v", "--verbose",
              description: "Print the verification and postinstall steps."
       switch "-n", "--dry-run",
diff --git a/docs/Manpage.md b/docs/Manpage.md
index 851b1e9777..8fd20070d6 100644
--- a/docs/Manpage.md
+++ b/docs/Manpage.md
@@ -252,7 +252,7 @@ the installed formulae or, every 30 days, for all formulae.
 * `-d`, `--debug`:
   If brewing fails, open an interactive debugging session with access to IRB or a shell inside the temporary build directory.
 * `-f`, `--force`:
-  Install formulae without checking for previously installed keg-only or non-migrated versions. Overwrite existing files when installing casks.
+  Install formulae without checking for previously installed keg-only or non-migrated versions. When installing casks, overwrite existing files (binaries and symlinks are excluded, unless originally from the same cask).
 * `-v`, `--verbose`:
   Print the verification and postinstall steps.
 * `--formula`:
@@ -608,7 +608,7 @@ upgraded formulae or, every 30 days, for all formulae.
 * `-d`, `--debug`:
   If brewing fails, open an interactive debugging session with access to IRB or a shell inside the temporary build directory.
 * `-f`, `--force`:
-  Install formulae without checking for previously installed keg-only or non-migrated versions. Overwrite existing files when installing casks.
+  Install formulae without checking for previously installed keg-only or non-migrated versions. When installing casks, overwrite existing files (binaries and symlinks are excluded, unless originally from the same cask).
 * `-v`, `--verbose`:
   Print the verification and postinstall steps.
 * `-n`, `--dry-run`:
diff --git a/manpages/brew.1 b/manpages/brew.1
index 7225af07be..de34878e5f 100644
--- a/manpages/brew.1
+++ b/manpages/brew.1
@@ -320,7 +320,7 @@ If brewing fails, open an interactive debugging session with access to IRB or a
 .
 .TP
 \fB\-f\fR, \fB\-\-force\fR
-Install formulae without checking for previously installed keg\-only or non\-migrated versions\. Overwrite existing files when installing casks\.
+Install formulae without checking for previously installed keg\-only or non\-migrated versions\. When installing casks, overwrite existing files (binaries and symlinks are excluded, unless originally from the same cask)\.
 .
 .TP
 \fB\-v\fR, \fB\-\-verbose\fR
@@ -815,7 +815,7 @@ If brewing fails, open an interactive debugging session with access to IRB or a
 .
 .TP
 \fB\-f\fR, \fB\-\-force\fR
-Install formulae without checking for previously installed keg\-only or non\-migrated versions\. Overwrite existing files when installing casks\.
+Install formulae without checking for previously installed keg\-only or non\-migrated versions\. When installing casks, overwrite existing files (binaries and symlinks are excluded, unless originally from the same cask)\.
 .
 .TP
 \fB\-v\fR, \fB\-\-verbose\fR