It should. There's a reason for that. :)
What's the reason, and why didn't they just use URNs?
The reason is because they're based off the same principle. "ARN" stands for "Amazon Resource Name".
I don't know why they didn't use URNs. Probably because nobody else does.
I think the implication is meant to be "they look like URNs because they are".
Except that they're not; rather, they're ARNs. URNs must begun with 'urn:'. It doesn't make a lot of sense that they're not URNs, but…they're not.
<!-- AWS Elastic Beanstalk application version --> arn:aws:elasticbeanstalk:us-east-1:123456789012:environment/My App/MyEnvironment
<!-- IAM user name --> arn:aws:iam::123456789012:user/David
<!-- Amazon RDS tag --> arn:aws:rds:eu-west-1:001234567890:db:mysql-db
<!-- Amazon S3 bucket (and all objects in it)--> arn:aws:s3:::my_corporate_bucket/*
http://docs.aws.amazon.com/general/latest/gr/aws-arns-and-na...