Typo
Thanks to Shay for pointing out some typos in my last post. The correct bits are
[alias("alias_name")]
[datatype]
[AllowNull()]
[AllowEmptyString()]
[AllowEmptyCollection()]
[ValidateCount(1,n)]
[ValidateLength(1,m)]
[ValidatePattern("[A-Z][A-Z]A-Z][0-9]")]
[ValidateRange(0,10)]
[ValidateScript({$_ -lt 4})]
[ValidateSet("red","blue","green")]
[ValidateNotNull()]
[ValidateNotNullOrEmpty()]
Apologies for the error