In many cases these are just recommendations and sometimes I have heard them expressed for the bank's systems, not customers.
While this is a safer route to follow, I always worry that it will lead to the sticky note stuck on the monitor. I think it may also be relaxed if you have stringent controls in place on the number and variation of characters in the first place, such as the inability to use a dictionary word and the requirement to use one or more non-alphanumeric characters.
Bottom line, if it is a written rule, and it could be, I haven't seen it. So I think it is urban legend at this point.
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AndyZ CRCM
My opinions are not necessarily my employers.
R+R-R=R+R
Rules and Regs minus Relationships equals Resentment and Rebellion. John Maxwell