Find the fields used by a template, excluding the standard template fields in Sitecore PowerShell Extensions.

ExcludeStandardFields.ps1

# Create a list of field names on the Standard Template. This will help us filter out extraneous fields.
$standardTemplate = Get-Item -Path "master:" -ID ([Sitecore.TemplateIDs]::StandardTemplate.ToString())
$standardTemplateTemplateItem = [Sitecore.Data.Items.TemplateItem]$standardTemplate
$standardFields = $standardTemplateTemplateItem.OwnFields + $standardTemplateTemplateItem.Fields | Select-Object -ExpandProperty key -Unique

# Change the Id to something other than the Sample Item template.
$itemTemplate = Get-Item -Path "master:" -ID "{76036F5E-CBCE-46D1-AF0A-4143F9B557AA}"
$itemTemplateTemplateItem = [Sitecore.Data.Items.TemplateItem]$itemTemplate
$itemTemplateFields = $itemTemplateTemplateItem.OwnFields + $itemTemplateTemplateItem.Fields | Select-Object -ExpandProperty key -Unique

$filterFields = $itemTemplateFields | Where-Object { $standardFields -notcontains $_ } | Sort-Object