diff --git a/command.py b/command.py
index 78dab96d..997acec0 100644
--- a/command.py
+++ b/command.py
@@ -230,3 +230,8 @@ class MirrorSafeCommand(object):
   """Command permits itself to run within a mirror,
      and does not require a working directory.
   """
+
+class RequiresGitcCommand(object):
+  """Command that requires GITC to be available, but does
+     not require the local client to be a GITC client.
+  """
diff --git a/main.py b/main.py
index adfaffb0..a5979a87 100755
--- a/main.py
+++ b/main.py
@@ -42,6 +42,7 @@ from git_command import git, GitCommand
 from git_config import init_ssh, close_ssh
 from command import InteractiveCommand
 from command import MirrorSafeCommand
+from command import RequiresGitcCommand
 from subcmds.version import Version
 from editor import Editor
 from error import DownloadError
@@ -143,6 +144,11 @@ class _Repo(object):
             file=sys.stderr)
       return 1
 
+    if isinstance(cmd, RequiresGitcCommand) and not gitc_utils.get_gitc_manifest_dir():
+      print("fatal: '%s' requires GITC to be available" % name,
+            file=sys.stderr)
+      return 1
+
     try:
       copts, cargs = cmd.OptionParser.parse_args(argv)
       copts = cmd.ReadEnvironmentOptions(copts)
diff --git a/repo b/repo
index 01c1cb0e..b7d8024f 100755
--- a/repo
+++ b/repo
@@ -214,6 +214,7 @@ group.add_option('--config-name',
                  help='Always prompt for name/e-mail')
 
 def _GitcInitOptions(init_optparse):
+  init_optparse.set_usage("repo gitc-init -u url -c client [options]")
   g = init_optparse.add_option_group('GITC options')
   g.add_option('-f', '--manifest-file',
                dest='manifest_file',
@@ -272,9 +273,12 @@ def _Init(args, gitc_init=False):
     if gitc_init:
       gitc_manifest_dir = get_gitc_manifest_dir()
       if not gitc_manifest_dir:
-        _print('error: GITC filesystem is not running. Exiting...',
+        _print('fatal: GITC filesystem is not available. Exiting...',
                file=sys.stderr)
         sys.exit(1)
+      if not opt.gitc_client:
+        _print('fatal: GITC client (-c) is required.', file=sys.stderr)
+        sys.exit(1)
       client_dir = os.path.join(gitc_manifest_dir, opt.gitc_client)
       if not os.path.exists(client_dir):
         os.makedirs(client_dir)
@@ -681,6 +685,10 @@ def _ParseArguments(args):
 
 
 def _Usage():
+  gitc_usage = ""
+  if get_gitc_manifest_dir():
+    gitc_usage = "  gitc-init Initialize a GITC Client.\n"
+
   _print(
 """usage: repo COMMAND [ARGS]
 
@@ -689,7 +697,8 @@ repo is not yet installed.  Use "repo init" to install it here.
 The most commonly used repo commands are:
 
   init      Install repo in the current working directory
-  help      Display detailed help on a command
+""" + gitc_usage +
+"""  help      Display detailed help on a command
 
 For access to the full online help, install repo ("repo init").
 """, file=sys.stderr)
@@ -701,6 +710,10 @@ def _Help(args):
     if args[0] == 'init':
       init_optparse.print_help()
       sys.exit(0)
+    elif args[0] == 'gitc-init':
+      _GitcInitOptions(init_optparse)
+      init_optparse.print_help()
+      sys.exit(0)
     else:
       _print("error: '%s' is not a bootstrap command.\n"
              '        For access to online help, install repo ("repo init").'
diff --git a/subcmds/gitc_init.py b/subcmds/gitc_init.py
index c0568caa..e99affa5 100644
--- a/subcmds/gitc_init.py
+++ b/subcmds/gitc_init.py
@@ -18,10 +18,11 @@ import os
 import sys
 
 import gitc_utils
+from command import RequiresGitcCommand
 from subcmds import init
 
 
-class GitcInit(init.Init):
+class GitcInit(init.Init, RequiresGitcCommand):
   common = True
   helpSummary = "Initialize a GITC Client."
   helpUsage = """
diff --git a/subcmds/help.py b/subcmds/help.py
index 4aa3f863..ae5b8f08 100644
--- a/subcmds/help.py
+++ b/subcmds/help.py
@@ -19,7 +19,8 @@ import sys
 from formatter import AbstractFormatter, DumbWriter
 
 from color import Coloring
-from command import PagedCommand, MirrorSafeCommand
+from command import PagedCommand, MirrorSafeCommand, RequiresGitcCommand
+import gitc_utils
 
 class Help(PagedCommand, MirrorSafeCommand):
   common = False
@@ -54,9 +55,17 @@ Displays detailed usage information about a command.
   def _PrintCommonCommands(self):
     print('usage: repo COMMAND [ARGS]')
     print('The most commonly used repo commands are:')
+
+    def gitc_supported(cmd):
+      if not isinstance(cmd, RequiresGitcCommand):
+        return True
+      if gitc_utils.get_gitc_manifest_dir():
+        return True
+      return False
+
     commandNames = list(sorted([name
                     for name, command in self.commands.items()
-                    if command.common]))
+                    if command.common and gitc_supported(command)]))
 
     maxlen = 0
     for name in commandNames: