Your manager has requested you to tag EC2 instances to organize and manage a load balancer. Which of the following
statements about tag restrictions is incorrect?

A.
The maximum key length is 127 Unicode characters.

B.
The maximum value length is 255 Unicode characters.

C.
Tag keys and values are case sensitive.

D.
The maximum number of tags per load balancer is 20.

Explanation:
Tags help you to categorize your load balancers in different ways, for example, by purpose, owner, or environment. The
following basic restrictions apply to tags: The maximum number of tags per resource is 10. The maximum key length is
127 Unicode characters. The maximum value length that can be used is 255 Unicode characters. The tag keys and
values are case sensitive. Allowed characters are letters, spaces, and numbers representable in UTF-8, plus the following
special characters: + – =. _ : / @. Do not use leading or trailing spaces. Do not use the aws: prefix in your tag names or
values because it is reserved for AWS use. You can’t edit or delete tag names or values with this prefix. Tags with this
prefix do not count against your tags per resource limit.
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/add-remove-tags.html#tag-restrictions