diff --git a/cmdline/cmdline.go b/cmdline/cmdline.go
index cc318be..ede3236 100644
--- a/cmdline/cmdline.go
+++ b/cmdline/cmdline.go
@@ -57,8 +57,11 @@
 	"io"
 	"io/ioutil"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
+	"unicode"
+	"unicode/utf8"
 
 	"v.io/x/lib/textutil"
 )
@@ -139,39 +142,44 @@
 type style int
 
 const (
-	styleDefault style = iota // Default style, good for cmdline output.
+	styleCompact style = iota // Default style, good for compact cmdline output.
+	styleFull                 // Similar to compact but shows global flags.
 	styleGoDoc                // Style good for godoc processing.
 )
 
 // String returns the human-readable representation of the style.
 func (s *style) String() string {
 	switch *s {
-	case styleDefault:
-		return "default"
+	case styleCompact:
+		return "compact"
+	case styleFull:
+		return "full"
 	case styleGoDoc:
 		return "godoc"
 	default:
-		panic(fmt.Errorf("Unhandled style %d", *s))
+		panic(fmt.Errorf("unhandled style %d", *s))
 	}
 }
 
 // Set implements the flag.Value interface method.
 func (s *style) Set(value string) error {
 	switch value {
-	case "default":
-		*s = styleDefault
+	case "compact":
+		*s = styleCompact
+	case "full":
+		*s = styleFull
 	case "godoc":
 		*s = styleGoDoc
 	default:
-		return fmt.Errorf("Unknown style %q", value)
+		return fmt.Errorf("unknown style %q", value)
 	}
 	return nil
 }
 
 // styleFromEnv returns the style value specified by the CMDLINE_STYLE
-// environment variable, falling back on the default style.
+// environment variable, falling back on styleCompact.
 func styleFromEnv() style {
-	style := styleDefault
+	style := styleCompact
 	style.Set(os.Getenv("CMDLINE_STYLE"))
 	return style
 }
@@ -223,7 +231,7 @@
 	fmt.Fprintln(w, cmd.Long)
 	fmt.Fprintln(w)
 	// Usage line.
-	hasFlags := numFlags(&cmd.Flags) > 0
+	hasFlags := numFlags(&cmd.Flags, nil, true) > 0
 	fmt.Fprintln(w, "Usage:")
 	path := cmd.namePath()
 	pathf := "   " + path
@@ -259,13 +267,13 @@
 		w.SetIndents(spaces(3), spaces(3+nameWidth+1))
 		for _, child := range cmd.Children {
 			// Don't repeatedly list default help command.
-			if !child.isDefaultHelp || firstCall {
+			if firstCall || !child.isDefaultHelp {
 				fmt.Fprintf(w, "%-[1]*[2]s %[3]s", nameWidth, child.Name, child.Short)
 				w.Flush()
 			}
 		}
 		w.SetIndents()
-		if firstCall {
+		if firstCall && style != styleGoDoc {
 			fmt.Fprintf(w, "Run \"%s help [command]\" for command usage.\n", path)
 		}
 	}
@@ -291,7 +299,7 @@
 			w.Flush()
 		}
 		w.SetIndents()
-		if firstCall {
+		if firstCall && style != styleGoDoc {
 			fmt.Fprintf(w, "Run \"%s help [topic]\" for topic details.\n", path)
 		}
 	}
@@ -299,13 +307,41 @@
 	if hasFlags {
 		fmt.Fprintln(w)
 		fmt.Fprintln(w, "The", path, "flags are:")
-		printFlags(w, &cmd.Flags, style)
+		printFlags(w, &cmd.Flags, style, nil, true)
 	}
 	// Global flags.
-	if numFlags(cmd.globalFlags) > 0 && firstCall {
-		fmt.Fprintln(w)
-		fmt.Fprintln(w, "The global flags are:")
-		printFlags(w, cmd.globalFlags, style)
+	hasCompact := numFlags(cmd.globalFlags, compactGlobalFlags, true) > 0
+	hasFull := numFlags(cmd.globalFlags, compactGlobalFlags, false) > 0
+	if firstCall {
+		if style == styleCompact {
+			if hasCompact {
+				fmt.Fprintln(w)
+				fmt.Fprintln(w, "The global flags are:")
+				printFlags(w, cmd.globalFlags, style, compactGlobalFlags, true)
+			}
+			if hasFull {
+				fmt.Fprintln(w)
+				fullhelp := fmt.Sprintf(`Run "%s help -style=full" to show all global flags.`, path)
+				if len(cmd.Children) == 0 {
+					if cmd.parent != nil {
+						fullhelp = fmt.Sprintf(`Run "%s help -style=full %s" to show all global flags.`, cmd.parent.namePath(), cmd.Name)
+					} else {
+						fullhelp = fmt.Sprintf(`Run "CMDLINE_STYLE=full %s -help" to show all global flags.`, path)
+					}
+				}
+				fmt.Fprintln(w, fullhelp)
+			}
+		} else {
+			if hasCompact || hasFull {
+				fmt.Fprintln(w)
+				fmt.Fprintln(w, "The global flags are:")
+				printFlags(w, cmd.globalFlags, style, compactGlobalFlags, true)
+				if hasCompact && hasFull {
+					fmt.Fprintln(w)
+				}
+				printFlags(w, cmd.globalFlags, style, compactGlobalFlags, false)
+			}
+		}
 	}
 }
 
@@ -318,15 +354,20 @@
 	return strings.Join(path, " ")
 }
 
-func numFlags(set *flag.FlagSet) (num int) {
-	set.VisitAll(func(*flag.Flag) {
-		num++
+func numFlags(set *flag.FlagSet, regexps []*regexp.Regexp, match bool) (num int) {
+	set.VisitAll(func(f *flag.Flag) {
+		if match == matchRegexps(regexps, f.Name) {
+			num++
+		}
 	})
 	return
 }
 
-func printFlags(w *textutil.LineWriter, set *flag.FlagSet, style style) {
+func printFlags(w *textutil.LineWriter, set *flag.FlagSet, style style, regexps []*regexp.Regexp, match bool) {
 	set.VisitAll(func(f *flag.Flag) {
+		if match != matchRegexps(regexps, f.Name) {
+			return
+		}
 		value := f.Value.String()
 		if style == styleGoDoc {
 			// When using styleGoDoc we use the default value, so that e.g. regular
@@ -344,6 +385,35 @@
 	return strings.Repeat(" ", count)
 }
 
+func matchRegexps(regexps []*regexp.Regexp, name string) bool {
+	// We distinguish nil regexps from empty regexps; the former means "all names
+	// match", while the latter means "no names match".
+	if regexps == nil {
+		return true
+	}
+	for _, r := range regexps {
+		if r.MatchString(name) {
+			return true
+		}
+	}
+	return false
+}
+
+var compactGlobalFlags []*regexp.Regexp
+
+// HideGlobalFlagsExcept hides global flags from the default compact-style usage
+// message, except for the given regexps.  Global flag names that match any of
+// the regexps will still be shown in the compact usage message.  Multiple calls
+// behave as if all regexps were provided in a single call.
+//
+// All global flags are always shown in non-compact style usage messages.
+func HideGlobalFlagsExcept(regexps ...*regexp.Regexp) {
+	compactGlobalFlags = append(compactGlobalFlags, regexps...)
+	if compactGlobalFlags == nil {
+		compactGlobalFlags = []*regexp.Regexp{}
+	}
+}
+
 // newDefaultHelp creates a new default help command.  We need to create new
 // instances since the parent for each help command is different.
 func newDefaultHelp() *Command {
@@ -358,11 +428,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 `,
 		ArgsName: "[command/topic ...]",
 		ArgsLong: `
@@ -376,7 +445,13 @@
 		},
 		isDefaultHelp: true,
 	}
-	help.Flags.Var(&helpStyle, "style", `The formatting style for help output, either "default" or "godoc".`)
+	help.Flags.Var(&helpStyle, "style", `
+The formatting style for help output:
+   compact - Good for compact cmdline output.
+   full    - Good for cmdline output, shows all global flags.
+   godoc   - Good for godoc processing.
+Override the default by setting the CMDLINE_STYLE environment variable.
+`)
 	return help
 }
 
@@ -413,8 +488,7 @@
 func recursiveHelp(w *textutil.LineWriter, cmd *Command, style style, firstCall bool) {
 	if !firstCall {
 		lineBreak(w, style)
-		// Title-case required for godoc to recognize this as a section header.
-		header := strings.Title(cmd.namePath())
+		header := godocSectionHeader(cmd.namePath())
 		fmt.Fprintln(w, header)
 		fmt.Fprintln(w)
 	}
@@ -427,18 +501,27 @@
 	}
 	for _, topic := range cmd.Topics {
 		lineBreak(w, style)
-		// Title-case required for godoc to recognize this as a section header.
-		header := strings.Title(cmd.namePath()+" "+topic.Name) + " - help topic"
+		header := godocSectionHeader(cmd.namePath() + " " + topic.Name + " - help topic")
 		fmt.Fprintln(w, header)
 		fmt.Fprintln(w)
 		fmt.Fprintln(w, topic.Long)
 	}
 }
 
+func godocSectionHeader(s string) string {
+	// The first rune must be uppercase for godoc to recognize the string as a
+	// section header, which is linked to the table of contents.
+	if s == "" {
+		return ""
+	}
+	r, n := utf8.DecodeRuneInString(s)
+	return string(unicode.ToUpper(r)) + s[n:]
+}
+
 func lineBreak(w *textutil.LineWriter, style style) {
 	w.Flush()
 	switch style {
-	case styleDefault:
+	case styleCompact, styleFull:
 		width := w.Width()
 		if width < 0 {
 			// If the user has chosen an "unlimited" word-wrapping width, we still
diff --git a/cmdline/cmdline_test.go b/cmdline/cmdline_test.go
index 44922b7..8f621c3 100644
--- a/cmdline/cmdline_test.go
+++ b/cmdline/cmdline_test.go
@@ -56,6 +56,7 @@
 
 type testCase struct {
 	Args        []string
+	Envs        map[string]string
 	Err         error
 	Stdout      string
 	Stderr      string
@@ -83,10 +84,17 @@
 		flagExtra = false
 		flagTopLevelExtra = false
 		optNoNewline = false
+		origEnvs := make(map[string]string)
 
-		fmt.Fprintf(os.Stderr, "running test %v\n", test.Args)
+		fmt.Fprintf(os.Stderr, "running test %v %v\n", test.Args, test.Envs)
 		os.Args = append([]string{os.Args[0]}, test.Args...)
-		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.PanicOnError)
+		flag.CommandLine = flag.NewFlagSet(os.Args[0], flag.ContinueOnError)
+		for k, v := range test.Envs {
+			origEnvs[k] = os.Getenv(k)
+			if err := os.Setenv(k, v); err != nil {
+				t.Fatalf("os.Setenv(%v, %v) failed: %v", k, v, err)
+			}
+		}
 
 		var globalFlag1 string
 		flag.StringVar(&globalFlag1, "global1", "", "global test flag 1")
@@ -99,13 +107,13 @@
 			flag.Parse()
 		}
 		if err := cmd.Execute(test.Args); err != test.Err {
-			t.Errorf("Ran with args %q\n GOT error:\n%q\nWANT error:\n%q", test.Args, err, test.Err)
+			t.Errorf("Ran with args %q envs %q\n GOT error:\n%q\nWANT error:\n%q", test.Args, test.Envs, err, test.Err)
 		}
 		if got, want := stripOutput(stdout.String()), test.Stdout; got != want {
-			t.Errorf("Ran with args %q\n GOT stdout:\n%q\nWANT stdout:\n%q", test.Args, got, want)
+			t.Errorf("Ran with args %q envs %q\n GOT stdout:\n%q\nWANT stdout:\n%q", test.Args, test.Envs, got, want)
 		}
 		if got, want := stripOutput(stderr.String()), test.Stderr; got != want {
-			t.Errorf("Ran with args %q\n GOT stderr:\n%q\nWANT stderr:\n%q", test.Args, got, want)
+			t.Errorf("Ran with args %q envs %q\n GOT stderr:\n%q\nWANT stderr:\n%q", test.Args, test.Envs, got, want)
 		}
 		if got, want := globalFlag1, test.GlobalFlag1; got != want {
 			t.Errorf("global1 flag got %q, want %q", got, want)
@@ -113,6 +121,12 @@
 		if got, want := *globalFlag2, test.GlobalFlag2; got != want {
 			t.Errorf("global2 flag got %q, want %q", got, want)
 		}
+
+		for k, v := range origEnvs {
+			if err := os.Setenv(k, v); err != nil {
+				t.Fatalf("os.Setenv(%v, %v) failed: %v", k, v, err)
+			}
+		}
 	}
 }
 
@@ -269,11 +283,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    onecmd help [flags] [command/topic ...]
@@ -281,8 +294,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The onecmd help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 
 The global flags are:
  -global1=
@@ -309,7 +326,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Onecmd Echo
+Onecmd echo
 
 Echo prints any strings passed in to stdout.
 
@@ -318,7 +335,7 @@
 
 [strings] are arbitrary strings that will be echoed.
 ================================================================================
-Onecmd Help
+Onecmd help
 
 Help with no args displays the usage of the parent command.
 
@@ -326,11 +343,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    onecmd help [flags] [command/topic ...]
@@ -338,8 +354,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The onecmd help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -503,7 +523,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Multi Echo
+Multi echo
 
 Echo prints any strings passed in to stdout.
 
@@ -512,7 +532,7 @@
 
 [strings] are arbitrary strings that will be echoed.
 ================================================================================
-Multi Echoopt
+Multi echoopt
 
 Echoopt prints any args passed in to stdout.
 
@@ -525,7 +545,7 @@
  -n=false
    Do not output trailing newline
 ================================================================================
-Multi Help
+Multi help
 
 Help with no args displays the usage of the parent command.
 
@@ -533,11 +553,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    multi help [flags] [command/topic ...]
@@ -545,8 +564,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The multi help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -856,7 +879,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Toplevelprog Echoprog
+Toplevelprog echoprog
 
 Echoprog has two variants of echo.
 
@@ -874,7 +897,7 @@
  -extra=false
    Print an extra arg
 ================================================================================
-Toplevelprog Echoprog Echo
+Toplevelprog echoprog echo
 
 Echo prints any strings passed in to stdout.
 
@@ -883,7 +906,7 @@
 
 [strings] are arbitrary strings that will be echoed.
 ================================================================================
-Toplevelprog Echoprog Echoopt
+Toplevelprog echoprog echoopt
 
 Echoopt prints any args passed in to stdout.
 
@@ -896,11 +919,11 @@
  -n=false
    Do not output trailing newline
 ================================================================================
-Toplevelprog Echoprog Topic3 - help topic
+Toplevelprog echoprog topic3 - help topic
 
 Help topic 3 long.
 ================================================================================
-Toplevelprog Hello
+Toplevelprog hello
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -909,7 +932,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Toplevelprog Help
+Toplevelprog help
 
 Help with no args displays the usage of the parent command.
 
@@ -917,11 +940,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    toplevelprog help [flags] [command/topic ...]
@@ -929,14 +951,18 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The toplevelprog help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 ================================================================================
-Toplevelprog Topic1 - help topic
+Toplevelprog topic1 - help topic
 
 Help topic 1 long.
 ================================================================================
-Toplevelprog Topic2 - help topic
+Toplevelprog topic2 - help topic
 
 Help topic 2 long.
 `,
@@ -1006,7 +1032,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Toplevelprog Echoprog Echo
+Toplevelprog echoprog echo
 
 Echo prints any strings passed in to stdout.
 
@@ -1015,7 +1041,7 @@
 
 [strings] are arbitrary strings that will be echoed.
 ================================================================================
-Toplevelprog Echoprog Echoopt
+Toplevelprog echoprog echoopt
 
 Echoopt prints any args passed in to stdout.
 
@@ -1028,7 +1054,7 @@
  -n=false
    Do not output trailing newline
 ================================================================================
-Toplevelprog Echoprog Help
+Toplevelprog echoprog help
 
 Help with no args displays the usage of the parent command.
 
@@ -1036,11 +1062,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    toplevelprog echoprog help [flags] [command/topic ...]
@@ -1048,10 +1073,14 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The toplevelprog echoprog help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 ================================================================================
-Toplevelprog Echoprog Topic3 - help topic
+Toplevelprog echoprog topic3 - help topic
 
 Help topic 3 long.
 `,
@@ -1379,7 +1408,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Prog1 Hello11
+Prog1 hello11
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1388,7 +1417,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Hello12
+Prog1 hello12
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1397,7 +1426,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2
+Prog1 prog2
 
 Prog2 has two variants of hello and a subprogram prog3.
 
@@ -1409,7 +1438,7 @@
    prog3       Set of hello commands
    hello22     Print strings on stdout preceded by "Hello"
 ================================================================================
-Prog1 Prog2 Hello21
+Prog1 prog2 hello21
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1418,7 +1447,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3
+Prog1 prog2 prog3
 
 Prog3 has two variants of hello.
 
@@ -1429,7 +1458,7 @@
    hello31     Print strings on stdout preceded by "Hello"
    hello32     Print strings on stdout preceded by "Hello"
 ================================================================================
-Prog1 Prog2 Prog3 Hello31
+Prog1 prog2 prog3 hello31
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1438,7 +1467,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3 Hello32
+Prog1 prog2 prog3 hello32
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1447,7 +1476,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Hello22
+Prog1 prog2 hello22
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1456,7 +1485,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Help
+Prog1 help
 
 Help with no args displays the usage of the parent command.
 
@@ -1464,11 +1493,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    prog1 help [flags] [command/topic ...]
@@ -1476,8 +1504,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The prog1 help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -1500,7 +1532,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Prog1 Prog2 Hello21
+Prog1 prog2 hello21
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1509,7 +1541,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3
+Prog1 prog2 prog3
 
 Prog3 has two variants of hello.
 
@@ -1520,7 +1552,7 @@
    hello31     Print strings on stdout preceded by "Hello"
    hello32     Print strings on stdout preceded by "Hello"
 ================================================================================
-Prog1 Prog2 Prog3 Hello31
+Prog1 prog2 prog3 hello31
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1529,7 +1561,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3 Hello32
+Prog1 prog2 prog3 hello32
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1538,7 +1570,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Hello22
+Prog1 prog2 hello22
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1547,7 +1579,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Help
+Prog1 prog2 help
 
 Help with no args displays the usage of the parent command.
 
@@ -1555,11 +1587,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    prog1 prog2 help [flags] [command/topic ...]
@@ -1567,8 +1598,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The prog1 prog2 help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -1590,7 +1625,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Prog1 Prog2 Prog3 Hello31
+Prog1 prog2 prog3 hello31
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1599,7 +1634,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3 Hello32
+Prog1 prog2 prog3 hello32
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1608,7 +1643,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3 Help
+Prog1 prog2 prog3 help
 
 Help with no args displays the usage of the parent command.
 
@@ -1616,11 +1651,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    prog1 prog2 prog3 help [flags] [command/topic ...]
@@ -1628,8 +1662,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The prog1 prog2 prog3 help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -1651,7 +1689,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Prog1 Prog2 Prog3 Hello31
+Prog1 prog2 prog3 hello31
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1660,7 +1698,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3 Hello32
+Prog1 prog2 prog3 hello32
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1669,7 +1707,7 @@
 
 [strings] are arbitrary strings that will be printed.
 ================================================================================
-Prog1 Prog2 Prog3 Help
+Prog1 prog2 prog3 help
 
 Help with no args displays the usage of the parent command.
 
@@ -1677,11 +1715,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    prog1 prog2 prog3 help [flags] [command/topic ...]
@@ -1689,8 +1726,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The prog1 prog2 prog3 help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -1705,7 +1746,6 @@
    hello12     Print strings on stdout preceded by "Hello"
    prog2       Set of hello commands
    help        Display help for commands or topics
-Run "prog1 help [command]" for command usage.
 
 The global flags are:
  -global1=
@@ -1713,7 +1753,7 @@
  -global2=0
    global test flag 2
 
-Prog1 Hello11
+Prog1 hello11
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1722,7 +1762,7 @@
 
 [strings] are arbitrary strings that will be printed.
 
-Prog1 Hello12
+Prog1 hello12
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1731,7 +1771,7 @@
 
 [strings] are arbitrary strings that will be printed.
 
-Prog1 Prog2
+Prog1 prog2
 
 Prog2 has two variants of hello and a subprogram prog3.
 
@@ -1743,7 +1783,7 @@
    prog3       Set of hello commands
    hello22     Print strings on stdout preceded by "Hello"
 
-Prog1 Prog2 Hello21
+Prog1 prog2 hello21
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1752,7 +1792,7 @@
 
 [strings] are arbitrary strings that will be printed.
 
-Prog1 Prog2 Prog3
+Prog1 prog2 prog3
 
 Prog3 has two variants of hello.
 
@@ -1763,7 +1803,7 @@
    hello31     Print strings on stdout preceded by "Hello"
    hello32     Print strings on stdout preceded by "Hello"
 
-Prog1 Prog2 Prog3 Hello31
+Prog1 prog2 prog3 hello31
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1772,7 +1812,7 @@
 
 [strings] are arbitrary strings that will be printed.
 
-Prog1 Prog2 Prog3 Hello32
+Prog1 prog2 prog3 hello32
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1781,7 +1821,7 @@
 
 [strings] are arbitrary strings that will be printed.
 
-Prog1 Prog2 Hello22
+Prog1 prog2 hello22
 
 Hello prints any strings passed in to stdout preceded by "Hello".
 
@@ -1790,7 +1830,7 @@
 
 [strings] are arbitrary strings that will be printed.
 
-Prog1 Help
+Prog1 help
 
 Help with no args displays the usage of the parent command.
 
@@ -1798,11 +1838,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    prog1 help [flags] [command/topic ...]
@@ -1810,8 +1849,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The prog1 help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 	}
@@ -1909,7 +1952,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Cmdargs Echo
+Cmdargs echo
 
 Echo prints any strings passed in to stdout.
 
@@ -1918,7 +1961,7 @@
 
 [strings] are arbitrary strings that will be echoed.
 ================================================================================
-Cmdargs Help
+Cmdargs help
 
 Help with no args displays the usage of the parent command.
 
@@ -1926,11 +1969,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    cmdargs help [flags] [command/topic ...]
@@ -1938,8 +1980,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The cmdargs help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -2101,7 +2147,7 @@
  -global2=0
    global test flag 2
 ================================================================================
-Cmdrun Echo
+Cmdrun echo
 
 Echo prints any strings passed in to stdout.
 
@@ -2110,7 +2156,7 @@
 
 [strings] are arbitrary strings that will be echoed.
 ================================================================================
-Cmdrun Help
+Cmdrun help
 
 Help with no args displays the usage of the parent command.
 
@@ -2118,11 +2164,10 @@
 
 "help ..." recursively displays help for all commands and topics.
 
-The output is formatted to a target width in runes.  The target width is
-determined by checking the environment variable CMDLINE_WIDTH, falling back on
-the terminal width from the OS, falling back on 80 chars.  By setting
-CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0 the width is unlimited, and
-if x == 0 or is unset one of the fallbacks is used.
+Output is formatted to a target width in runes, determined by checking the
+CMDLINE_WIDTH environment variable, falling back on the terminal width, falling
+back on 80 chars.  By setting CMDLINE_WIDTH=x, if x > 0 the width is x, if x < 0
+the width is unlimited, and if x == 0 or is unset one of the fallbacks is used.
 
 Usage:
    cmdrun help [flags] [command/topic ...]
@@ -2130,8 +2175,12 @@
 [command/topic ...] optionally identifies a specific sub-command or help topic.
 
 The cmdrun help flags are:
- -style=default
-   The formatting style for help output, either "default" or "godoc".
+ -style=compact
+   The formatting style for help output:
+      compact - Good for compact cmdline output.
+      full    - Good for cmdline output, shows all global flags.
+      godoc   - Good for godoc processing.
+   Override the default by setting the CMDLINE_STYLE environment variable.
 `,
 		},
 		{
@@ -2188,7 +2237,7 @@
 	runTestCases(t, prog, tests)
 }
 
-func TestLongCommandsHelp(t *testing.T) {
+func TestLongCommands(t *testing.T) {
 	cmdLong := &Command{
 		Name:  "thisisaverylongcommand",
 		Short: "the short description of the very long command is very long, and will have to be wrapped",
@@ -2247,3 +2296,135 @@
 	}
 	runTestCases(t, prog, tests)
 }
+
+func TestHideGlobalFlags(t *testing.T) {
+	HideGlobalFlagsExcept(regexp.MustCompile(`^global2$`))
+	cmdChild := &Command{
+		Name:  "child",
+		Short: "description of child command.",
+		Long:  "blah blah blah",
+		Run:   runEcho,
+	}
+	prog := &Command{
+		Name:     "program",
+		Short:    "Test hiding global flags.",
+		Long:     "Test hiding global flags.",
+		Children: []*Command{cmdChild},
+	}
+	var tests = []testCase{
+		{
+			Args: []string{"help"},
+			Stdout: `Test hiding global flags.
+
+Usage:
+   program <command>
+
+The program commands are:
+   child       description of child command.
+   help        Display help for commands or topics
+Run "program help [command]" for command usage.
+
+The global flags are:
+ -global2=0
+   global test flag 2
+
+Run "program help -style=full" to show all global flags.
+`,
+		},
+		{
+			Args: []string{"help", "child"},
+			Stdout: `blah blah blah
+
+Usage:
+   program child
+
+The global flags are:
+ -global2=0
+   global test flag 2
+
+Run "program help -style=full child" to show all global flags.
+`,
+		},
+		{
+			Args: []string{"help", "-style=full"},
+			Stdout: `Test hiding global flags.
+
+Usage:
+   program <command>
+
+The program commands are:
+   child       description of child command.
+   help        Display help for commands or topics
+Run "program help [command]" for command usage.
+
+The global flags are:
+ -global2=0
+   global test flag 2
+
+ -global1=
+   global test flag 1
+`,
+		},
+		{
+			Args: []string{"help", "-style=full", "child"},
+			Stdout: `blah blah blah
+
+Usage:
+   program child
+
+The global flags are:
+ -global2=0
+   global test flag 2
+
+ -global1=
+   global test flag 1
+`,
+		},
+	}
+	runTestCases(t, prog, tests)
+	compactGlobalFlags = nil
+}
+
+func TestHideGlobalFlagsRootNoChildren(t *testing.T) {
+	HideGlobalFlagsExcept(regexp.MustCompile(`^global2$`))
+	prog := &Command{
+		Name:  "program",
+		Short: "Test hiding global flags, root no children.",
+		Long:  "Test hiding global flags, root no children.",
+		Run:   runEcho,
+	}
+	var tests = []testCase{
+		{
+			Args: []string{"-help"},
+			Stdout: `Test hiding global flags, root no children.
+
+Usage:
+   program
+
+The global flags are:
+ -global2=0
+   global test flag 2
+
+Run "CMDLINE_STYLE=full program -help" to show all global flags.
+`,
+		},
+		{
+			Args: []string{"-help"},
+			Envs: map[string]string{"CMDLINE_STYLE": "full"},
+			Stdout: `Test hiding global flags, root no children.
+
+Usage:
+   program
+
+The global flags are:
+ -global2=0
+   global test flag 2
+
+ -global1=
+   global test flag 1
+`,
+		},
+	}
+	runTestCases(t, prog, tests)
+	compactGlobalFlags = nil
+}