If you have used AWS Elastic Load Balancers before, you might have come across this note while creating a new ELB:
Because the set of IP addresses associated with a LoadBalancer can change over time, you should never create an “A” record with any specific IP address. If you want to use a friendly DNS name for your load balancer instead of the name generated by the Elastic Load Balancing service, you should create a CNAME record for the LoadBalancer DNS name, or use Amazon Route 53 to create a hosted zone. For more information, see Using Domain Names With Elastic Load Balancing.
While CNAMEs would be suitable for most use cases, there are certain situations where CNAMEs do not fit business requirements. Like,