anchor.diff:  
   [discrete]
   [[set-tier-preference]]
  -=== Set a tier preference for existing indices.
  +==== Set a tier preference for existing indices.
   
   {ilm-init} automatically transitions managed indices through the available
   data tiers by automatically injecting a <<ilm-migrate,migrate action>>
  
positive.code: you can still use attribute-based allocation filters to
  control shard allocation for other purposes.
  
  To switch to using node roles:
  
  . <<assign-data-tier, Assign data nodes>> to the appropriate data tier.
  
negative.code: 
  [discrete]
  [[stop-setting-custom-hot-attribute]]
  ==== Stop setting the custom hot attribute on new indices
  
  When you create a data stream, its first backing index
  is now automatically assigned to `data_hot` nodes.
  