AWS SDK for .NET Documentation
DomainName Property
AmazonAmazon.CloudSearch_2011_02_01.ModelUpdateStemmingOptionsRequestDomainName Did this page help you?   Yes   No    Tell us about it...
A string that represents the name of a domain. Domain names must be unique across the domains owned by an account within an AWS region. Domain names must start with a letter or number and can contain the following characters: a-z (lowercase), 0-9, and - (hyphen). Uppercase letters and underscores are not allowed.

Constraints:

Length
3 - 28
Pattern
[a-z][a-z0-9\-]+

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

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