What does '*' symbol in /etc/passwd means?

[KiChang Yang]

I'm much interested in UNIX system.
Recently, I found this '*' curios symbol in /etc/passwd.
For example,
	bin:*:2:1::/bin:/bin/csh
Could you tell me what this symbol means?

Thanks in advance.

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!	e910276 at dal1.kaist.ac.kr					
!	Korea Institute of Technology.
!	   KiChang Yang.
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