what is the meaning of the !A in the output of the "traceroute" command?

[admin_2]

When I issue "traceroute" command,

I got some hops and then a !A and terminats. What does !A mean in the traceroute output?

[#2]

http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/fun_r/frprt3/frd3002.htm#94196

Administratively unreachable. Usually, this output indicates that an access list is blocking traffic.