Comment 1 for bug 516486

The underlying issue here is that Amazon's EC2 API and AMI tools don't use "-a", "-s" consistently. The API tools are SOAP based and so "-a" and "-s" are mapped as tool specific parameters. But the AMI tools are REST based and use "-a" and "-s" for the access key and secret key. One of the complains from users was that they had to rewrite their EC2 based scripts and change the meaning of "-s" for commands such as "*-authorize"

So, the decision was made to make sure that "-a" and "-s" map to tool specific parameters and in these cases, "-A" and "-S" are used to represent the access key and secret key. In practice, the access key and secret key should not be specified on the command line, so this was thought to be the least disruptive way to fix the problem.

Clearly, this fix was left out of "euca-describe-images" Revno 244 fixes this.