How to exclude material from Phyiscal invty count (LI11)

Dear Gurus,

Please tell how to exclude material which as marked as "Obsoleted in Plant" in Physical inventory count.

When i am running Transaction LI11 and find out that i need to add a new item to the PI count and if by mistake i enter a material which is Obsoleted in Plant, the system is not givin me an error.

hope i am clear in my question...

Regards,

Kumar