diff --git a/contrib/wix/help.wxs b/contrib/wix/help.wxs
--- a/contrib/wix/help.wxs
+++ b/contrib/wix/help.wxs
@@ -23,6 +23,7 @@
           <File Name="environment.txt" />
           <File Name="extensions.txt" />
           <File Name="filesets.txt" />
+          <File Name="flags.txt" />
           <File Name="glossary.txt" />
           <File Name="hgignore.txt" />
           <File Name="hgweb.txt" />
diff --git a/mercurial/help.py b/mercurial/help.py
--- a/mercurial/help.py
+++ b/mercurial/help.py
@@ -224,6 +224,7 @@
     (['color'], _("Colorizing Outputs"), loaddoc('color')),
     (["config", "hgrc"], _("Configuration Files"), loaddoc('config')),
     (["dates"], _("Date Formats"), loaddoc('dates')),
+    (["flags"], _("Command-line flags"), loaddoc('flags')),
     (["patterns"], _("File Name Patterns"), loaddoc('patterns')),
     (['environment', 'env'], _('Environment Variables'),
      loaddoc('environment')),
diff --git a/mercurial/help/flags.txt b/mercurial/help/flags.txt
new file mode 100644
--- /dev/null
+++ b/mercurial/help/flags.txt
@@ -0,0 +1,53 @@
+Most Mercurial commands accept various flags.
+
+Flag types
+==========
+
+Mercurial command-line flags can be strings, numbers, booleans, or lists of
+strings.
+
+Specifying boolean flags
+========================
+
+Boolean flags do not take a value parameter. To specify a boolean, use the flag
+name to set it to true, or the same name prefixed with 'no-' to set it to
+false::
+
+    hg commit --interactive
+    hg commit --no-interactive
+
+Specifying list flags
+=====================
+
+List flags take multiple values. To specify them, pass the flag multiple times::
+
+    hg files --include mercurial --include tests
+
+Setting flag defaults
+=====================
+
+In order to set a default value for a flag in an hgrc file, set it under the
+[defaults] section of the hgrc file::
+
+    [defaults]
+    commit = --interactive
+
+For more information on hgrc files, see :hg:help:config.
+
+Overriding flag defaults
+========================
+
+Every flag has a default value, and you may also set your own defaults in hgrc
+as described above.
+Except for list flags, defaults can be overridden on the command line simplify
+by specifying the flag in that location.
+
+Hidden flags
+============
+
+Some flags are not shown in a command's help by default - specifically, those
+that are deemed to be experimental, deprecated or advanced. To show all flags,
+add the --verbose flag for the help command::
+
+    hg help --verbose commit
+
diff --git a/tests/test-globalopts.t b/tests/test-globalopts.t
--- a/tests/test-globalopts.t
+++ b/tests/test-globalopts.t
@@ -355,6 +355,7 @@
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
+   flags         Command-line flags
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
@@ -439,6 +440,7 @@
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
+   flags         Command-line flags
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
diff --git a/tests/test-help.t b/tests/test-help.t
--- a/tests/test-help.t
+++ b/tests/test-help.t
@@ -110,6 +110,7 @@
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
+   flags         Command-line flags
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
@@ -188,6 +189,7 @@
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
+   flags         Command-line flags
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
@@ -865,6 +867,7 @@
    environment   Environment Variables
    extensions    Using Additional Features
    filesets      Specifying File Sets
+   flags         Command-line flags
    glossary      Glossary
    hgignore      Syntax for Mercurial Ignore Files
    hgweb         Configuring hgweb
@@ -2010,6 +2013,13 @@
   Specifying File Sets
   </td></tr>
   <tr><td>
+  <a href="/help/flags">
+  flags
+  </a>
+  </td><td>
+  Command-line flags
+  </td></tr>
+  <tr><td>
   <a href="/help/glossary">
   glossary
   </a>
diff --git a/tests/test-hgweb-json.t b/tests/test-hgweb-json.t
--- a/tests/test-hgweb-json.t
+++ b/tests/test-hgweb-json.t
@@ -1581,6 +1581,10 @@
         "topic": "filesets"
       },
       {
+        "summary": "Command-line flags",
+        "topic": "flags"
+      },
+      {
         "summary": "Glossary",
         "topic": "glossary"
       },