Merge pull request #650 from QuinnyPig/tag-caveat

Tag case-sensitivy gotcha

README.md

@@ -536,6 +536,7 @@ So if you’re not going to manage your AWS configurations manually, what should
 	-	To (once enabled) [allocate cost](https://docs.aws.amazon.com/awsaccountbilling/latest/aboutv2/cost-alloc-tags.html). Note that cost allocation tags only apply on a forward-looking basis; you can't retroactively apply them to items already billed.
 	-	For many years, there was a notorious 10 tag limit per resource, which could not be raised and caused many companies significant pain. As of 2016, this was [raised](https://aws.amazon.com/blogs/security/now-organize-your-aws-resources-by-using-up-to-50-tags-per-resource/) to 50 tags per resource.
 	-	🔹In 2017, AWS introduced the ability to [enforce tagging](https://aws.amazon.com/blogs/aws/new-tag-ec2-instances-ebs-volumes-on-creation/) on instance and volume creation, deprecating portions of third party tools such as [Cloud Custodian](https://github.com/capitalone/cloud-custodian).
+	-	🔸 Tags are case sensitve; 'environment' and 'Environment' are two different tags. Automation in setting tags is likely the only sensible option at significant scale.
 	-	🔸 There is a bug in the ASG console where spaces after tag names are preserved. So if you type "Name " with a space at the end you will not get the expected behavior. This is probably true in other locations and SDKs also. Be sure you do not add trailing spaces to tag keys unless you really mean it. (As of Jul 2018)
 
 Managing Servers and Applications