Explanation/Reference:

Explanation
Clastic Load Balancing provides access logs that capture detailed information about requests sent to your load balancer. Cach log contains information such as the time the request was received, the client's IP address, latencies, request paths, and server responses. You can use these access logs to analyze traffic patterns and to troubleshoot issues.
Access logging is an optional feature of Elastic Load Balancing that is disabled by default. After you enable access logging for your load balancer. Clastic Load Balancing captures the logs and stores them in the Amazon S3 bucket that you specify. You can disable access logging at any time.
For more information on CLB access logs, please refer to the below document link: from AWS
* http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/access-log-collection.html

Explanation
The below snapshot from the AWS documentation gives details on the Networkln metric.

Explanation
You can use intrinsic functions, such as Fn::lf, Fn::Cquals, and Fn::Not, to conditionally create stack resources. These conditions are evaluated based on input parameters that you declare when you create or update a stack. After you define all your conditions, you can associate them with resources or resource properties in the Resources and Outputs sections of a template.
For more information on Cloud Formation template functions, please refer to the URL:
* http://docs.aws.amazon.com/AWSCIoudFormation/latest/UserGuide/intrinsic-function-reference.html and
* http://docs.aws.amazon.com/AWSCIoudFormation/latest/UserGuide/intrinsic-function-reference-conditions.html

Snapshots shared with other users are usable in full by the recipient, including but limited to the ability to base modified volumes and snapshots.
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ebs-modifying-snapshot- permissions.html