Private/Get-ValidADPReturn.ps1

function Get-ValidADPReturn {
    <#
    .SYNOPSIS
        Validate a string by removing invalid characters

    .DESCRIPTION
        Helper function to help with getting a valid string

    .PARAMETER InputString
        String that needs to be validated. Accepts pipe value

    .EXAMPLE
        Input String: th is is a test
        Return String: th is is a test

    .NOTES
        This removes any bad characters

    .FUNCTIONALITY
        Powershell Language
    #>

    [CmdletBinding()]
    param (
        [Parameter( Position = 0,
            ValueFromPipeline = $true
        )]
        [string]$InputString
    )
    if ($InputString) {
        $InputString = $InputString.Replace(' ', ' ')
        $InputString = $InputString.Replace('ß', "ss")
        $InputString = $InputString.Replace('ü', "u")
        $InputString = $InputString.Trim()
    }

    return $InputString
}