Apache RewriteRule Flag error

Question

I'm having problems with the follow code:

Options FollowSymLinks
RewriteEngine on
RewriteRule ^thing/([^/]+)/?$  index.php?t=$1 [B]

I'm getting "500 Internal Server Error"

The error log says:

RewriteRule: unknown flag 'B'

I've check my Apache version:

[root@server ~]# httpd -v
Server version: Apache/2.2.3
Server built:   Jan 21 2009 22:00:55

What am I missing?

(Note: the page loads without the [B] flag)

Answer 1

[B] was new in 2.2.7.