Change numbers

Hi

I have created a change number , First time when i changed the Bom in cs02 using this change number there was no error message

The second time i changed the bom using cs02 , i did not enter change number and i got error message bom has history requirement .

I have seen in several threads that i have to check the authorisation

check the authorization for this object in that particular user id,

C_STUE_NOH,whether its No or Yes.

Is it possible that if my freind enters the cs02 and changes the bom he wont get the error message ?

Does this message come only after we start changing the Bom with change number ?