When I came on board at my current employer some years ago the resignation policy was very fair. It was detailed in the employee handbook as well as at orientation.
Simply you should stay for two weeks or for the amount of vacation time you have left whichever is greater.
I thought this was a fair policy and considering everything else was OK you would leave under good terms and would be considered a rehire.
Though about one and a half years ago there was an undocumented HR policy change that is always spoken about when somebody resigns. It's always spoken about by management and people always so follow the new guidelines even if the meet the specifications above.
The new undocumented policy is
You must give 30 days notice. Failure to give 30 days notice will result HR flagging you as a non rehire no matter the standing of employee. The company also has a strict policy that all reference for past employees cannot be given by management but must be given by HR.
Given that previous employers can only legally say whether they would or would not rehire the employee makes for quite the conundrum.
Employees are now essentially forced to give 30 days notice if they want to use this company as a reference and may lose potential future opportunities (some companies may not want to wait 30 days) all because of an undocumented policy.
How does one deal with this?