anchor.diff:  ++++
   
   You can change how the lifecycle of an index or collection of rolling indices is managed
  -by modifying the current policy or switching to a different policy. 
  +by modifying the current policy or switching to a different policy.
   
  -To ensure that policy updates don't put an index into a state where it can't exit the current phase,
  -the phase definition is cached in the index metadata when it enters the phase. 
  -This cached definition is used to complete the phase. 
  +To ensure that policy updates don't put an index into a state where it can't
  +exit the current phase, the phase definition is cached in the index metadata
  +when it enters the phase. If changes can be safely applied, {ilm-init} updates
  +the cached phase definition. If they cannot, phase execution continues using
  +the cached definition.
   
   When the index advances to the next phase, it uses the phase definition from the updated policy.
   
  
positive.code: Changes to `min_age` are not propagated to the cached definition.
  Changing a phase's `min_age` does not affect indices that are currently executing that phase.
  
  For example, if you create a policy that has a hot phase that does not specify a `min_age`, 
  indices immediately enter the hot phase when the policy is applied. 
  If you then update the policy to specify a `min_age` of 1 day for the hot phase, 
  that has no effect on indices that are already in the hot phase.
  Indices created _after_ the policy update won't enter the hot phase until they are a day old.
  
  
negative.code: [[ilm-apply-new-policy]]
  === How new policies are applied
  
  When you apply a different policy to a managed index,
  the index completes the current phase using the cached definition from the previous policy.
  The index starts using the new policy when it moves to the next phase.
  