How can ignore more than one commands from history?

If we 开发者_开发技巧want to remove one command from history we can use,

For Example,

export HISTIGNORE="ls" -> It will remove the ls command from history.

But I want to know how to ignore more than one commands from history?

Thanks in Advance.

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Input the list with commands separated by colons:

export HISTIGNORE="&:ls:[bf]g:exit"