That seems promising, I'll look into using a custom field. You can close this ticket, thank you.

Searching through Maniphest tasks in Phabricator

My feature request was not about asking users to fill in additional fields. It was about providing a keywords field that could be parsed during a search in case specific keywords might not be in the title or in the content of the phab. This is a feature that is part of many knowledgebases, and it allows additional search terms for a specific article or item without having to just type a bunch of words into the actual content.