ipcs

I am working with a shared memory application, and to delete the segments I use the following command: ipcrm -M 0x0000162e (this is the key) But I do not know if I'm doing the right things, because when I run ipcs I see the same segment but with the key 0x0000000. So is the memory segment really deleted? When I run my application several times I see different memory segments with the key 0x000000, like this: key shmid owner perms bytes nattch status 0x00000000 65538 me 666 27 2 dest 0x00000000 98307 me 666 5 2 dest 0x00000000 131076 me 666 5 1 dest 0x00000000 163845 me 666 5 0 What is actually