KQL Syntax question

[Gary Bushey]

I was looking at the KQL for one of the charts in a workbook and came across this statement that I cannot figure out what it does.

AppDisplayName in ('*') or '*' in ('*')

The full statement up to that part is 

let data = SigninLogs

    | extend AppDisplayName = iff(AppDisplayName == '', 'Unknown', AppDisplayName)

    | where AppDisplayName in ('*') or '*' in ('*')

Anyone know what that statement means?

[#2 · Accepted solution]

@Gary Bushey 

https://docs.microsoft.com/en-us/azure/kusto/query/inoperator

in allows you to to use a list.  so where AppDisplayName in ('*') is saying basically where appdisplayname is populated.

[#3]

@Nicholas DiCola (SECURITY JEDI) So does

"*" in ("*")

Mean

A) If any column has data

B) if all columns have data

C) Something entirely different?

[#4]

@Gary Bushey 

since its an or it should be A