Update 31.markdown
:help match will explain the `match()`.
    
        | author | nkalvi <nkalvi@users.noreply.github.com> | 
    
        | date | Sun, 27 Dec 2015 07:11:34 -0500 | 
    
    
        | parents | 56683eb09ecc | 
    
        | children | 9f23058cc187 | 
    
        | branches/tags | (none) | 
    
        | files | chapters/31.markdown | 
Changes
    
--- a/chapters/31.markdown	Thu Apr 04 01:38:14 2013 -0400
+++ b/chapters/31.markdown	Sun Dec 27 07:11:34 2015 -0500
@@ -184,7 +184,7 @@
 Read `:help pattern-overview` to see the kinds of things Vim regexes support.
 Stop reading after the character classes.
 
-Read `:help match`.  Try running the `:match Error /\v.../` command a few times
+Read `:help :match`.  Try running the `:match Error /\v.../` command a few times
 by hand.
 
 Edit your `~/.vimrc` file to add a mapping that will use `match` to highlight