Assigning the filter to a document function code After you create a document function code, assign a filter to text attachments. Open the Filter form. Specify the Header, Labs, and security for the filter. Specify the document codes for the attached files or URLs only. Do not add embedded image codes. The INSTRUC code is not required for the formula and item filters. INSTRUC is not displayed in the Notes tab for the formula. The code is displayed in the Notes tab for the item.