def is_filter_only(alias_properties):
  """Determine if alias is for filter use only.

  Prevents alias filters from being exportable.

  Args:
    alias_properties: Alias properties.
  Returns:
    Boolean reflecting if it's filter only or not.
  """
  if isinstance(alias_properties, dict):
    if alias_properties.get("filter_only"):
      return True
  return False