diff --git a/runtime/doc/usr_41.txt b/runtime/doc/usr_41.txt
index f0e1ee5..f34891a 100644
--- a/runtime/doc/usr_41.txt
+++ b/runtime/doc/usr_41.txt
@@ -1,4 +1,4 @@
-*usr_41.txt*	For Vim version 8.2.  Last change: 2021 Mar 14
+*usr_41.txt*	For Vim version 8.2.  Last change: 2021 Apr 19
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -115,12 +115,20 @@
 
 FOUR KINDS OF NUMBERS
 
-Numbers can be decimal, hexadecimal, octal or binary.  A hexadecimal number
-starts with "0x" or "0X".  For example "0x1f" is decimal 31.  An octal number
-starts with a zero.  "017" is decimal 15.  A binary number starts with "0b" or
-"0B".  For example "0b101" is decimal 5.  Careful: don't put a zero before a
-decimal number, it will be interpreted as an octal number!
-   The ":echo" command always prints decimal numbers.  Example: >
+Numbers can be decimal, hexadecimal, octal or binary.
+
+A hexadecimal number starts with "0x" or "0X".  For example "0x1f" is decimal
+31.
+
+An octal number starts with "0o", "0O" or a zero and another digit.  "0o17" is
+decimal 15.  Using just a zero prefix is not supported in Vim9 script.
+
+A binary number starts with "0b" or "0B".  For example "0b101" is decimal 5.
+
+A decimal number is just digits.  Careful: don't put a zero before a decimal
+number, it will be interpreted as an octal number in legacy script!
+
+The ":echo" command always prints decimal numbers.  Example: >
 
 	:echo 0x7f 0o36
 <	127 30 ~