diff --git a/CHANGELOG b/CHANGELOG
index f4ab581..2dc7e44 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,15 @@
+Buku v4.0
+2018-11-01
+
+What's in?
+- Show records in pages with option `-p` (works with `-n`, default 10)
+- Enhanced clipboard support: `xclip`, tmux, GNU Screen, Termux
+- Prompt key `O` works with search results along with GUI browser toggling
+- Search by taglist id with prompt key `g`
+- Multiple fixes
+
+-------------------------------------------------------------------------------
+
 Buku v3.9
 2018-08-30
 
diff --git a/README.md b/README.md
index 52c3501..20a51a6 100644
--- a/README.md
+++ b/README.md
@@ -261,6 +261,8 @@ SYMBOLS:
 
 PROMPT KEYS:
     1-N                    browse search result indices and/or ranges
+    O [id|range [...]]     open search results/indices in GUI browser
+                           toggle try GUI browser if no arguments
     a                      open all results in browser
     s keyword [...]        search for records with ANY keyword
     S keyword [...]        search for records with ALL keywords
@@ -275,7 +277,6 @@ PROMPT KEYS:
     p id|range [...]       print bookmarks by indices and/or ranges
     w [editor|id]          edit and add or update a bookmark
     c id                   copy url at search result index to clipboard
-    O                      toggle try to open in a GUI browser
     ?                      show this help
     q, ^D, double Enter    exit buku
 ```
diff --git a/buku.1 b/buku.1
index c9a29f5..d2617b2 100644
--- a/buku.1
+++ b/buku.1
@@ -1,4 +1,4 @@
-.TH "BUKU" "1" "30 Aug 2018" "Version 3.9" "User Commands"
+.TH "BUKU" "1" "01 Nov 2018" "Version 4.0" "User Commands"
 .SH NAME
 buku \- Bookmark manager like a text-based mini-web
 .SH SYNOPSIS
@@ -301,6 +301,9 @@ Show debug information and additional logs.
 .BI "1-N"
 Browse search results by indices and ranges.
 .TP
+.BI "O" "[id|range [...]]"
+Try to open search results or indices (when not in a search context) in a GUI browser. Toggle try to open urls in a GUI based browser (even if BROWSER is set) if no arguments. Toggling is useful when trying to open bookmarks by DB index.
+.TP
 .BI "a"
 Open all search results in browser.
 .TP
@@ -334,9 +337,6 @@ Edit and add or update a bookmark.
 .BI "c id"
 Copy url at search result index to clipboard.
 .TP
-.BI "O"
-Toggles ignore text-based browsers. If enabled, tries to open urls in a GUI based browser (even if BROWSER is set).
-.TP
 .BI "?"
 Show help on prompt keys.
 .TP
diff --git a/buku.py b/buku.py
index 5131cc1..dc64850 100755
--- a/buku.py
+++ b/buku.py
@@ -45,7 +45,7 @@ from urllib3.exceptions import LocationParseError
 from urllib3.util import parse_url, make_headers
 import webbrowser
 
-__version__ = '3.9'
+__version__ = '4.0'
 __author__ = 'Arun Prakash Jana <engineerarun@gmail.com>'
 __license__ = 'GPLv3'
 
@@ -2660,8 +2660,8 @@ Webpage: https://github.com/jarun/Buku
         file.write('''
 PROMPT KEYS:
     1-N                    browse search result indices and/or ranges
-    O [id|range [...]]     open search result/indices in GUI browser
-                           toggle try GUI browser if no options
+    O [id|range [...]]     open search results/indices in GUI browser
+                           toggle try GUI browser if no arguments
     a                      open all results in browser
     s keyword [...]        search for records with ANY keyword
     S keyword [...]        search for records with ALL keywords