diff --git a/dvc/command/gc.py b/dvc/command/gc.py
index 67c0927d2e..b4b710ae73 100644
--- a/dvc/command/gc.py
+++ b/dvc/command/gc.py
@@ -80,27 +80,27 @@ def add_parser(subparsers, parent_parser):
         "--workspace",
         action="store_true",
         default=False,
-        help="Keep data files used in the current workspace.",
+        help="Keep data files used in the current workspace (working tree).",
     )
     gc_parser.add_argument(
         "-a",
         "--all-branches",
         action="store_true",
         default=False,
-        help="Keep data files for the tips of all git branches.",
+        help="Keep data files for the tips of all Git branches.",
     )
     gc_parser.add_argument(
         "-T",
         "--all-tags",
         action="store_true",
         default=False,
-        help="Keep data files for all git tags.",
+        help="Keep data files for all Git tags.",
     )
     gc_parser.add_argument(
         "--all-commits",
         action="store_true",
         default=False,
-        help=argparse.SUPPRESS,
+        help="Keep data files for all Git commits.",
     )
     gc_parser.add_argument(
         "-c",
diff --git a/dvc/repo/__init__.py b/dvc/repo/__init__.py
index 5912d5dc57..5850f0f56b 100644
--- a/dvc/repo/__init__.py
+++ b/dvc/repo/__init__.py
@@ -229,7 +229,7 @@ def used_cache(
         (namely, a file described as an output on a stage).
 
         The scope is, by default, the working directory, but you can use
-        `all_branches` or `all_tags` to expand scope.
+        `all_branches`/`all_tags`/`all_commits` to expand the scope.
 
         Returns:
             A dictionary with Schemes (representing output's location) as keys,
diff --git a/dvc/repo/brancher.py b/dvc/repo/brancher.py
index 955b135135..67a3b19b36 100644
--- a/dvc/repo/brancher.py
+++ b/dvc/repo/brancher.py
@@ -9,9 +9,9 @@ def brancher(  # noqa: E302
     """Generator that iterates over specified revisions.
 
     Args:
-        branches (list): a list of branches to iterate over.
+        revs (list): a list of revisions to iterate over.
         all_branches (bool): iterate over all available branches.
-        tags (list): a list of tags to iterate over.
+        all_commits (bool): iterate over all commits.
         all_tags (bool): iterate over all available tags.
 
     Yields:
diff --git a/scripts/completion/dvc.bash b/scripts/completion/dvc.bash
index 004685410c..135f706619 100644
--- a/scripts/completion/dvc.bash
+++ b/scripts/completion/dvc.bash
@@ -26,7 +26,7 @@ _dvc_fetch='-j --jobs -r --remote -a --all-branches -T --all-tags -d --with-deps
 _dvc_fetch_COMPGEN=_dvc_compgen_DVCFiles
 _dvc_get_url=''
 _dvc_get='-o --out --rev --show-url'
-_dvc_gc='-a --all-branches -T --all-tags -c --cloud -r --remote -f --force -p --projects -j --jobs'
+_dvc_gc='-a --all-branches --all-commits -T --all-tags -w --workspace -c --cloud -r --remote -f --force -p --projects -j --jobs'
 _dvc_import_url='-f --file'
 _dvc_import='-o --out --rev'
 _dvc_init='--no-scm -f --force'
diff --git a/scripts/completion/dvc.zsh b/scripts/completion/dvc.zsh
index af97520e00..49c9ecf22d 100644
--- a/scripts/completion/dvc.zsh
+++ b/scripts/completion/dvc.zsh
@@ -128,8 +128,10 @@ _dvc_get=(
 )
 
 _dvc_gc=(
-  {-a,--all-branches}"[Keep data files for the tips of all git branches.]"
-  {-T,--all-tags}"[Keep data files for all git tags.]"
+  {-w,--workspace}"[Keep data files used in the current workspace (working tree).]"
+  {-a,--all-branches}"[Keep data files for the tips of all Git branches.]"
+  "--all-commits[Keep data files for all Git commits.]"
+  {-T,--all-tags}"[Keep data files for all Git tags.]"
   {-c,--cloud}"[Collect garbage in remote repository.]"
   {-r,--remote}"[Remote storage to collect garbage in.]:Remote repository:"
   {-f,--force}"[Force garbage collection - automatically agree to all prompts.]:Repos:_files"