SharePoint: Mysterious parameter name g

Powershell.part2.ps1

function Add-SPUserSolutionProperties
{
    <#
        .Synopsis
            This function will allow you to add additional properties to a Sandboxed solution
        .Description
            This function will add the additional Sandboxed solution information specified under the " #Sandboxed Solution Properties " comment tag
        .Example
            C:\> Add-SPUserSolutionProperties –SiteUrl “http://yourdomain.com/sites/Finance –SolutionName My.Sandboxed.Solution -SolutionId 6b701ca1-9c46-452f-8f91-73799ffb24fa -SolutionHash 8JfkvlDR9eTUcdZb1GDncs+hhqy8wZPd0oEh2GIK/20=
        .Notes
            Name: Add-SPUserSolutionProperties
            Author: Petro Margaritis
            Last Edit: 04/07/2012
            Keywords: Sandboxed Solution, Troubleshooting, Properties
        .Link
            https://www.iampetro.com/
    #>
    Param (
        [parameter(Mandatory=$true)][string]$SiteUrl,
        [parameter(Mandatory=$true)][string]$SolutionName,
        [parameter(Mandatory=$true)][string]$SolutionId,
        [parameter(Mandatory=$true)][string]$SolutionHash,
        [parameter(Mandatory=$false)][int]$SolutionHasAssemblies,
        [parameter(Mandatory=$false)][string]$vti_cachedcustomprops
    )

    $web = Get-SPWeb $SiteUrl
    # Access the Solution Gallery of the Site Collection
    $solGallery = $web.Lists["Solution Gallery"]
    # You will first need to identify the solutions ID number in the gallery
    $solID = ($solGallery.Items | Where-Object {$_.displayName -eq $SolutionName}).ID

    # Access the Solution in question
    if ($solID -ne $null)
    {
        $solution = $solGallery.GetItemById($solID)

        # Sandboxed Solution Properties
        $solution.Properties["SolutionId"] = $SolutionId
        $solution.Properties["SolutionHash"] = $SolutionHash
        if ($SolutionHasAssemblies -ne $null)
        {
            $solution.Properties["SolutionHasAssemblies"] = $SolutionHasAssemblies
        }
            if ($vti_cachedcustomprops -ne $null)
        {
            $solution.Properties["vti_cachedcustomprops"] = $vti_cachedcustomprops
        }

        # Apply the changes
        $solution.Update()

        Write-Host "The Sandboxed Solution has been updated successfully" -foregroundcolor Green
    }
    else
    {
        Write-Host "The Sandboxed Solution could not be found, please ensure you have entered the correct Solution name and that it has been uploaded to the Solution Gallery in the" $web.Title "Site Collection" -foregroundcolor Yellow
    }

    # Dispose of the SPWeb object
    $web.Dispose()
}