AWS SDK for .NET Documentation
UserData Property
AmazonAmazon.AutoScaling.ModelLaunchConfigurationUserData Did this page help you?   Yes   No    Tell us about it...
The user data available to the launched Amazon EC2 instances.

Constraints:

Length
0 - 21847
Pattern
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*

Declaration Syntax
C#
public string UserData { get; set; }

Assembly: AWSSDK (Module: AWSSDK) Version: 1.5.60.0 (1.5.60.0)