One sort of "hidden" feature of the Indexed I/O system is the ability to endorse images based on project tags. For example, if you wanted a set of documents in your production to be marked "Attorneys Eye's Only" you could tag those items as such, and then apply an endorsement that will mark items with that tag as "Attorneys Eye's Only" (Or whatever tag name you would like to use).
To use this feature, start your export as normal, then at step 6 of 7 enter "tag:tag_id_here" into the endorsement field (without quotes) as seen below. Make sure there are no spaces in this string.
Replace "tag_id_here" with the ID of the tag you want to use. The tag ID can be found by navigating to the tags tab from the project home page, then clicking edit next to the tag whose ID you want to look up.
Once you click edit, a new window will pop up with information about that tag. The ID can be found at the top as seen below.
You can enter multiple tags separated by commas like seen here:
If all tags entered are applied to a document, then all will be stamped, and as expected if only some of the tags are applied only those will be stamped on the document.